Devices, systems and methods for medicament delivery

ABSTRACT

An apparatus includes a movable member and a valve coupled to the movable member. The movable member is configured to be disposed within a housing of a medical device and has a first end portion and second end portion. A portion of the first end portion is configured to define a portion of a boundary of a gas chamber. The first end portion defines an opening configured to be in fluid communication between the gas chamber and an area outside the gas chamber. The second end portion is configured to be coupled to a needle configured to deliver a medicament into a body. The valve is configured to selectively allow fluid communication between the gas chamber and the area outside the gas chamber through the opening defined by the first end portion of the movable member.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/875,085, entitled “Devices, Systems and Methods for MedicamentDelivery,” filed Oct. 5, 2015, which is a continuation of U.S. patentapplication Ser. No. 13/748,728, now U.S. Pat. No. 9,149,579, entitled“Devices, Systems and Methods for Medicament Delivery,” filed Jan. 24,2013, which is a continuation of U.S. patent application Ser. No.13/090,392, now U.S. Pat. No. 8,361,029, entitled “Devices, Systems andMethods for Medicament Delivery,” filed Apr. 20, 2011, which is acontinuation of U.S. patent application Ser. No. 11/566,422, now U.S.Pat. No. 7,947,017, entitled “Devices, Systems and Methods forMedicament Delivery,” filed Dec. 4, 2006. This application is related toU.S. patent application Ser. No. 10/515,571, now U.S. Pat. No.7,416,540, entitled “Devices, Systems and Methods for MedicamentDelivery,” filed Nov. 23, 2004, which is a national stage filing under35 U.S.C. § 371 of International Patent Application No.PCT/US2004/039386, entitled “Devices, Systems and Methods for MedicamentDelivery,” filed Nov. 23, 2004, each of which is incorporated herein byreference in its entirety. This application is also related to U.S.patent application Ser. No. 10/572,148, now U.S. Pat. No. 7,749,194,entitled “Devices, Systems and Methods for Medicament Delivery,” filedMar. 16, 2006, which is a national stage filing under 35 U.S.C. § 371 ofInternational Patent Application No. PCT/US2006/003415, entitled“Devices, Systems and Methods for Medicament Delivery,” filed Feb. 1,2006, which claims priority to U.S. Provisional Application Ser. No.60/648,822, entitled “Devices, Systems and Methods for MedicamentDelivery,” filed Feb. 1, 2005 and U.S. Provisional Application Ser. No.60/731,886, entitled “Auto-Injector with Feedback,” filed Oct. 31, 2005.Each of the above referenced applications is incorporated herein byreference in its entirety.

BACKGROUND

The invention relates generally to a medical device, and moreparticularly to an auto-injector for injecting a medicament into a bodyof a patient.

Exposure to certain substances, such as, for example, peanuts,shellfish, bee venom, certain drugs, toxins, and the like, can causeallergic reactions in some individuals. Such allergic reactions can, attimes, lead to anaphylactic shock, which can cause a sharp drop in bloodpressure, hives, and/or severe airway constriction. Accordingly,responding rapidly to mitigate the effects from such exposures canprevent injury and/or death. For example, in certain situations, aninjection of epinephrine (i.e., adrenaline) can provide substantialand/or complete relief from the allergic reaction. In other situations,for example, an injection of an antidote to a toxin can greatly reduceand/or eliminate the harm potentially caused by the exposure.

Because emergency medical facilities may not be available when anindividual is suffering from an allergic reaction, some individualscarry an auto-injector to rapidly self-administer a medicament inresponse to an allergic reaction. Some known auto-injectors arecylindrical in shape and include a spring loaded needle to automaticallypenetrate the user's skin and inject the medicament. Such knownauto-injectors can be bulky and conspicuous, which can make carryingthem inconvenient and undesirable. Moreover, some known auto-injectorsdo not have a retractable needle and, as such, cause a sharps hazardwhen injection is complete.

Some known auto-injectors use pressurized gas to insert a needle and/orinject a medicament into the patient. Such known auto-injectors often donot include a mechanism for completely releasing or venting thepressurized gas upon completion of the injection event.

Thus, a need exists for an auto-injector that can be more convenientlycarried by a user and does not present a sharps hazard upon completionof the injection. Furthermore, a need exists for a gas-poweredauto-injector that has an improved gas release mechanism.

SUMMARY

Apparatuses and methods for automatic medicament injection are describedherein. In one embodiment, an apparatus includes a movable member and avalve coupled to the movable member. The movable member is configured tobe disposed within a housing of a medical device and has a first endportion and second end portion. A portion of the first end portion isconfigured to define a portion of a boundary of a gas chamber. The firstend portion defines an opening configured to be in fluid communicationbetween the gas chamber and an area outside the gas chamber. The secondend portion is configured to be coupled to a needle configured todeliver a medicament into a body. The valve is configured to selectivelyallow fluid communication between the gas chamber and the area outsidethe gas chamber through the opening defined by the first end portion ofthe movable member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a system according to an embodiment ofthe invention.

FIG. 2 is a front view of a system according to an embodiment of theinvention.

FIG. 3 is a side view of a system according to an embodiment of theinvention.

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3 of asystem according to an embodiment of the invention in a first operativeposition.

FIG. 5 is a cross-sectional view taken along line A-A of FIG. 3 of asystem according to an embodiment of the invention in a second operativeposition.

FIG. 6 is a cross-sectional view taken along line A-A of FIG. 3 of asystem according to an embodiment of the invention in a third operativeposition.

FIG. 7 is a cross-sectional view taken along line A-A of FIG. 3 of asystem according to an embodiment of the invention in a fourth operativeposition.

FIG. 8 is a cross-sectional view taken along line A-A of FIG. 3 of asystem according to an embodiment of the invention in a fifth operativeposition.

FIG. 9 is a cross-sectional view taken along line A-A of FIG. 3 of asystem according to an embodiment of the invention in a sixth operativeposition.

FIG. 10 is a flowchart illustrating a method according to an embodimentof the invention.

FIG. 11 is a perspective view of a system according to an embodiment ofthe invention.

FIG. 12 is a perspective cross-sectional view the system illustrated inFIG. 11 taken along line B-B of FIG. 11.

FIG. 13 is a perspective view of an apparatus according to an embodimentof the invention.

FIG. 14 is a cross-sectional view of a mechanism according to anembodiment of the invention taken along line A-A of FIG. 3.

FIGS. 15 and 16 are schematic illustrations of an auto-injectoraccording to an embodiment of the invention in a first configuration anda second configuration, respectively.

FIG. 17 is a perspective view of an auto-injector according to anembodiment of the invention.

FIG. 18 is a perspective view of the auto-injector illustrated in FIG.17 in a first configuration, with at least a portion of theauto-injector illustrated in phantom lines for ease of reference.

FIG. 19 is a front view of the auto-injector illustrated in FIGS. 17 and18 in a first configuration.

FIG. 20 is a perspective view of the auto-injector illustrated in FIG.17 showing an assembly according to an embodiment of the invention beingremoved.

FIG. 21 is a front view of the auto-injector illustrated in FIG. 17showing a member according to an embodiment of the invention beingremoved.

FIG. 22 is an exploded perspective view of a portion of theauto-injector illustrated in FIG. 20.

FIG. 23 is a cross-sectional view of a component illustrated in FIG. 21.

FIG. 24 is a perspective view of a component illustrated in FIG. 21.

FIG. 25 is a perspective view of a member of the auto-injectorillustrated in FIG. 21.

FIG. 26 is a perspective view of a portion of the auto-injectorillustrated in FIGS. 17 and 21.

FIG. 27 is a perspective view of a portion of the auto-injectorillustrated in FIGS. 17 and 26.

FIG. 28 is a partially exploded perspective view of a base of theauto-injector illustrated in FIG. 26.

FIG. 29 is an exploded perspective view of a portion of theauto-injector shown in FIG. 21.

FIG. 30 is a front view of a component of the auto-injector shown inFIG. 29.

FIG. 31 is a front view of the auto-injector illustrated in FIG. 19 in asecond configuration.

FIG. 32 is a perspective view of a portion of the auto-injector shown inFIG. 31.

FIGS. 33 and 34 are perspective views of a portion of the auto-injectorshown in FIG. 32.

FIG. 35 is a top view of the housing of the auto-injector shown in FIG.31.

FIG. 36 is a cross-sectional view of the housing taken along line 36-36in FIG. 35.

FIG. 37 is front view of the auto-injector illustrated in FIGS. 19 and31 in a third configuration.

FIG. 38 is a front view of the portion of the auto-injector labeled as38 in FIG. 37.

FIG. 39 is a perspective view of a portion of the auto-injector shown inFIG. 37.

FIG. 40 is a cross-sectional view of a portion of the auto-injector asshown in FIG. 37.

FIG. 41 is a perspective view of a portion of the auto-injector as shownin FIG. 37.

FIG. 42 is an exploded perspective view of a portion the auto-injectoras shown in FIG. 37.

FIG. 43 is front view of the auto-injector illustrated in FIGS. 19, 31and 38 in a fourth configuration.

FIG. 44 is a front view of a portion of the auto-injector illustrated inFIGS. 19, 31, 38 and 43 in a fifth configuration.

FIG. 45 is a front view of the auto-injector illustrated in FIGS. 19,31, 38, 43 and 44 in a sixth configuration.

FIGS. 46-48 are schematic illustrations of an auto-injector according toan embodiment of the invention in a first configuration, a secondconfiguration and a third configuration, respectively.

FIGS. 49 and 50 are schematic illustrations of an auto-injectoraccording to an embodiment of the invention in a first configuration anda second configuration, respectively.

FIGS. 51-53 are schematic illustrations of an auto-injector according toan embodiment of the invention in a first configuration, a secondconfiguration and a third configuration, respectively.

FIGS. 54 and 55 are schematic illustrations of a portion of anauto-injector according to an embodiment of the invention in a firstconfiguration and a second configuration, respectively.

FIG. 56 is a schematic illustration of an auto-injector according to anembodiment of the invention in a first configuration.

FIGS. 57-60 are schematic illustrations of a portion of theauto-injector labeled as 57-60 in FIG. 56 in a second configuration, athird configuration, a fourth configuration and a fifth configuration,respectively.

FIG. 61 is a plot showing the pressure within the auto-injector shown inFIG. 56 as a function of the position of a portion of the auto-injector.

DETAILED DESCRIPTION

Apparatuses and methods for automatic medicament injection are describedherein. In some embodiments, an apparatus includes a movable member anda valve coupled to the movable member. The movable member is configuredto be disposed within a housing of a medical device and has a first endportion and second end portion. A portion of the first end portion isconfigured to define a portion of a boundary of a gas chamber. The firstend portion defines an opening configured to be in fluid communicationbetween the gas chamber and an area outside the gas chamber. The secondend portion is configured to be coupled to a needle configured todeliver a medicament into a body. The valve is configured to selectivelyallow fluid communication between the gas chamber and the area outsidethe gas chamber through the opening defined by the first end portion ofthe movable member.

In some embodiments, an apparatus includes a movable member, a valve andan actuator. The valve and the actuator are each coupled to the movablemember. The movable member is configured to be disposed within a housingof a medical device and has a first end portion and second end portion.A portion of the first end portion is configured to define a portion ofa boundary of a gas chamber. The first end portion defines an openingconfigured to be in fluid communication between the gas chamber and anarea outside the gas chamber. The second end portion is configured to becoupled to a needle configured to deliver a medicament into a body. Thevalve is configured to selectively allow fluid communication between thegas chamber and the area outside the gas chamber through the openingdefined by the first end portion of the movable member. The actuator isconfigured to move the valve between a first position and a secondposition. When the valve is in the first position the gas chamber isfluidically isolated from the area outside the gas chamber. When thevalve is in the second position the gas chamber is in fluidcommunication with the area outside the gas chamber.

In some embodiments, an apparatus includes a housing, a medicamentcontainer, a medicament injector, an injection member and a valve. Thehousing defines a gas chamber. The medicament container is configured tobe movably disposed within the housing and defines a portion of aboundary of the gas chamber. The medicament injector includes a sealconfigured to engage a portion of the housing to fluidically isolate thegas chamber from an area outside the gas chamber. A portion of themedicament injector is engaged with a medicament container that ismovably disposed within the housing. The injection member, which can be,for example, a needle, defines a lumen configured to be in fluidcommunication with the medicament container and is configured to conveya medicament from the medicament container into a body of a patient. Themedicament injector has a first position and a second position. When inthe first position, the injection member is contained within thehousing. When in the second position, a portion of the injection memberextends from the housing. The valve, which can be disposed on themedicament injector, has a first configuration and a secondconfiguration. When the valve is in the first configuration, the gaschamber is fluidically isolated from the area outside the gas chamber.When the valve is in the second configuration, the gas chamber is influid communication with the area outside the gas chamber.

In some embodiments, an apparatus includes a housing defining a gaschamber, a movable member and a gas release assembly. The movable memberhas a first portion and a second portion. The first portion defines aportion of a boundary of the gas chamber. The second portion isconfigured to be coupled to a needle that can deliver a medicament intoa body. The movable member is disposable within the housing in a firstposition and a second position. When the movable member is in the firstposition, the needle is disposed within the housing. When the movablemember is in the second position, a portion of the needle extendsoutside the housing. The gas release assembly, which can include, forexample, a valve, an actuator and a passageway between the gas chamberand an area outside of the gas chamber, has a first configuration and asecond configuration. When the gas release system is in its firstconfiguration, the gas chamber is fluidically isolated from the areaoutside the gas chamber. When the gas release system is in its secondconfiguration, the gas chamber is in fluid communication with the areaoutside the gas chamber. The gas release assembly is configured to bemoved from its first configuration to its second configuration when themovable member is in its second position. The gas release system isfurther configured to be maintained in its second configurationindependent of the position of the movable member.

In some embodiments, an apparatus includes a housing defining a gaschamber, a movable member and a valve. The movable member is configuredto move longitudinally within the housing. The movable member has afirst portion and a second portion. The first portion defines a portionof a boundary of the gas chamber. The second portion is configured tomove a plunger within a medicament container to expel a medicamentcontained within the medicament container. The valve defines a flowpassageway between the gas chamber and an area outside the gas chamber.The flow passageway has a flow area that varies as a function of alongitudinal position of the movable member.

FIG. 1 is a perspective view, FIG. 2 is a front view, and FIG. 3 is aside view, of a system 1000 according to the invention, which cancomprise a housing 1100, which, in some embodiments, can comprise ahandheld portion 1800 separated via an actuation guard 1200 from anactuation bar 1300. Actuation guard 1200 can prevent accidentalactivation of system 1000. Housing 1100 can be constructed of a durablematerial, such as stainless steel, aluminum, polycarbonate, etc., toprotect a compressed gas container, medicament, injection apparatusand/or user of system 1000. The injection apparatus can be actuated by afluid pressure, such as pressure provided by the compressed gas, whichupon completion of actuation can escape housing 1100 via gas escapeopening, such as via status indicator 1400.

A status of a system 1000 can be determined via status indicator 1400,which can provide a view, such as via a UV blocking, photo-sensitive,and/or translucent window, into an interior of housing 1100. Viewablethrough the window can be a status of medicament carried by housing1100, a location of a needle and/or injection apparatus for themedicament, and/or an activation status of system 1000. For example, ifthe medicament has aged to the point of discoloration, which aging mightor might not render the medication useless, harmful, etc., statusindicator 1400 can allow that situation to be determined. In someembodiments, gas can escape housing 1100 via status indicator 1400and/or another opening in housing 1100.

Some embodiments of system 1000 can provide a compact medicamentdelivery mechanism that can efficiently and/or rapidly deliver aprescribed dose. The length (L) and width (W) of system 1000 can besimilar to that of a credit card, and the thickness (T) can be less thanone inch. Thus, some embodiments of system 1000 can provide aconveniently carried, easy-to-use, easy to activate drug deliveryapparatus that can require little to no training to safely carry, use,and/or dispose of.

To assist a user in positioning system 1000 in a correct orientation forinjection, system 1000 and/or housing 1100 can provide various tactileclues. For example, a top 1110 of housing 1100 can be rounded, and abottom 1120 of actuation bar 1300 of housing 1100 can be flat. Othertactile clues are also possible, such as bulges, ribs, grooves, gaps,roughened surfaces, indentations, etc.

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3 of anembodiment of a system 1000 in a first operative position. FIGS. 5, 6,7, 8, and 9 show system 1000 of FIG. 4 in second, third, fourth, fifth,and sixth operative positions, respectively.

System 1000 can comprise a housing 1100, handheld portion 1800,actuation guard 1200, and/or actuation bar 1300. System 1000 cancomprise system actuator 2000, gas reservoirs 3000, medicament actuator4000, medicament storage assembly 5000, medicament carrier 9000, needleassembly 6000, use indicator 7000, and/or gas vent mechanism 8000, etc.

Upon removal, release, rotation, and/or relocation of actuation guard1200, system actuator 2000 can be adapted to rapidly discharge anactuating portion of a contents of a compress gas container. Forexample, system actuator 2000 can comprise a compressed gas container2400, which initially can contain a compressed gas 2500, an actuatingportion of which can be released from container 2400 by penetration of agas port 2600 via a point of a puncturer 2700. Upon removal and/orrelocation of actuation guard 1200, actuation bar 1300 can be movedcloser to and/or in contact with handheld portion 1800. Upon removaland/or relocation of actuation guard 1200, gas container 2400 can bebrought into contact with puncturer 2700 via extension of apre-compressed spring 2300 and/or movement of an actuation stick 2200.Thus, actuation guard 1200 can prevent accidental activation of system1000 and/or unintended discharge of an actuating portion of the contents2500 of gas container 2400.

Once gas port 2600 has been punctured, an actuating portion ofcompressed gas 2500 can escape from container 2400 and flow via gasreservoirs 3000, such as gas channel 3100. The flowing gas can meetand/or apply gas pressure to medicament actuator 4000, which cancomprise a pusher 4100, which can travel within a sleeve 1500 defined bywalls 1520. Sleeve 1500 can be constructed of metal, stainless steel,aluminum, plastic, polycarbonate, etc. Seals 4200, such as o-rings, canresist gas leakage, such as past pusher 4100 and/or out of housing 1100.Thus, pusher 4100 can function as a piston traveling within a cylinder,although it is not necessarily required that the cross-sectional shapeof sleeve 1500 be round.

Medicament actuator 4000 can interface with medicament storage assembly5000. For example, medicament actuator 4000 can comprise a plurality ofplungers 4300, each of which can be capped with a piston 4400 which cansealingly slide and/or move within a corresponding vial 5100 containinga liquid medicament 5200. For example, in response to pressure appliedby an actuating portion of the contents 2500 of compressed gas container2400, pusher 4100 can cause plungers 4300 and/or pistons 4400 tosimultaneously move. The number of corresponding sets of plungers 4300,pistons 4400, and/or vials 5100 can be 2, 3, 4, 5, 6, or more. Pistons4400 can be constructed of a resilient, durable, and/or sealingmaterial, such as a rubber. Each plunger 4300 from the plurality ofplungers can define a longitudinal axis, the longitudinal axes (e.g.,axes 4310, 4320, 4330, 4340) of the plurality of plungers can beparallel, non-coaxial, and/or co-planar.

Each vial 5100 from the plurality of vials can be substantiallycylindrical with a substantially round and/or substantially ellipticalcross-sectional shape. Thus, each vial 5100 can define a longitudinalaxis, the longitudinal axes of the plurality of vials can be parallel,non-coaxial, and/or co-planar. The longitudinal axis of each vial can beco-axial with the longitudinal axis of its corresponding plunger.

Each vial can be capped at one end with a frangible seal 5300, which canbe burst when piston 4400 generates sufficient pressure upon medicament5200, thereby allowing at least a portion of medicament 5200 to flow outof vial 5100 and into medicament carrier 9000. Thus, the plurality ofvials can be fluidly coupleable to the actuating portion of the contents2500 of gas container 2400.

Medicament carrier 9000 can hold each of vials 5100 and can travelwithin sleeve 1500. Medicament carrier 9000 can comprise a plurality ofchannels 9200 adapted to receive medicament 5200 as it exits itsrespective vial 5100, and direct medicament 5200 to a common conduit9300. Medicament carrier 9000 can interface with needle assembly 6000and/or use indicator 7000.

From common conduit 9300, medicament 5200 can enter needle assembly6000, such as into a single needle 6100 via which medicament canapproach needle tip 6200. As medicament actuator 4000 and/or medicamentcarrier 9000 are driven toward actuator bar 1300, needle tip 6200 canpenetrate an end 6400 of needle sheath 6300 and exit actuator bar 1300at needle port 1340.

Referring to FIG. 5, upon movement of actuation bar 1300 closer tohandheld portion 1800, sheath seat 1330 can come in contact with sheathtip 6400, thereby causing sheath 6300 to buckle and/or crumble. Asactuator bar 1300 comes in contact with handheld portion 1800, bar stop1320 can approach medicament carrier stop 9400, while carrier spring1600 is compressed.

Referring to FIG. 6, as at least a portion of contents 2500 of gascontainer 2400 escapes, it can flow through channel 3100. The gas, whichcan still be relatively pressurized, can begin to accumulate behindpusher 4100 to form an expanding gas chamber 3200 and to causemedicament actuator 4000, medicament storage assembly 5000, andmedicament carrier 9000 to slide together within sleeve 1500. Asmedicament actuator 4000, medicament storage assembly 5000, andmedicament carrier 9000 slide closer to actuator bar 1300, spring 1600becomes increasingly compressed between bar stop 1320 and medicamentcarrier stop 9400. As medicament actuator 4000, medicament storageassembly 5000, and medicament carrier 9000 slide closer to actuator bar1300, needle tip 6200 can extend further from actuator bar 1300 andsheath 6300 can become further compressed and/or deformed. At itsultimate extension point, needle tip 6200 can extend from housing 1100from approximately 0.25 millimeters to approximately 20 millimeters,including all values and subranges therebetween, such as up toapproximately 2 millimeters, greater than approximately 5 millimeters,from approximately 5.13 millimeters to approximately 9.98 millimeters,etc.

Referring to FIG. 7, as gas chamber 3200 continues to expand, medicamentcarrier 9000 can be driven until medicament carrier stop 9400 contactsactuator bar stop 1300 thereby resisting further travel of medicamentcarrier 9000. At that point, additional expansion of gas chamber 3200can cause medicament actuator 4000, pusher 4100, plungers 4300, and/orpistons 4400 to initiate travel with respect to medicament storageassembly 5000, thereby generating an expulsion pressure in vials 5100,and/or thereby rupturing frangible seals 5300 and allowing medicament5200 to enter medicament carrier 9000, and begin flowing throughmedicament channels 9200, medicament conduit 9300, needle 6100, and/orout needle tip 6200 and into a patient. Alternatively, frangible seals5300 can be replaced and/or augmented by a frangible seal located at ornear where medicament conduit 9300 couples to needle 6100. Frangibleseals 5300 can be constructed of a thin, taught, resilient, durable,and/or sealing material potentially having a predetermined yieldstrength, such as a rubber, such as chromo butyl rubber, and/or of arelatively brittle material potentially having a predetermined yieldstrength, such as ceramic, certain plastics, such as polystyrene, etc.

As medicament carrier stop 9400 contacts actuator bar stop 1320,medicament carrier hooks 9600 can engage with engagement receivers 7100in use indicator 7000.

Referring to FIG. 8, as gas chamber 3200 continues to expand, medicamentactuator 4000, pusher 4100, plungers 4300, and/or pistons 4400 cancontinue moving until they complete their travel within medicamentstorage assembly 5000, thereby expelling a predetermined dose ofmedicament 5200 from vials 5100, out of needle assembly 6000, externalto housing 1100, and/or into the patient. As gas chamber 3200 reachesits maximum size, medicament actuator 4000, pusher 4100, plungers 4300,and/or pistons 4400 can continue moving until they complete their travelwith respect to medicament carrier 9000, thereby causing gas releaseactuator 9700 to engage with gas relief valve 8200. Engagement of gasrelease actuator 9700 with gas relief valve 8200 can cause gas withingas chamber 3200 to exit gas chamber 3200, discharge away from pistons4400, and/or exhaust from system 1000 and/or housing 1100, such as viastatus indicator 1400 and/or a gas escape port located on housing 1100).

Referring to FIG. 8 and FIG. 9, as sufficient gas is vented from gaschamber 3200, the pressure applied by the gas in gas chamber 3200 candecrease until the force applied by the gas on medicament actuator 4000is less than the force of compressed spring 1600. Thus, spring(s) 1600can begin to expand, thereby moving medicament carrier 9000, vialassembly 5000, and medicament actuator 4000 away from actuator bar 1300and helping to exhaust gas from gas chamber 3200. As medicament carrier9000 moves, use indicator 7000 can travel with it, due to the engagedrelationship of medicament carrier hooks 9600 and engagement receivers7100 and/or engagement catches 7200 in use indicator 7000. As useindicator 7000 moves away from actuation bar 1300, sheath 6300 cantravel with it, thereby creating a gap between sheath tip 6400 andneedle port 1340, and thereby exposing a previously non-visible coloredportion 1350 of actuation bar 1300 and/or providing an indication thatsystem 1000 has been used (and likely substantially exhausted of itsmedicament), thereby discouraging any further attempts to use system1000.

As medicament carrier 9000 moves away from actuator bar 1300, needle6100 can retract into sheath 6300 which un-buckles and/or un-deformstowards its original shape. Eventually, needle 6100 can retractcompletely within the boundaries of housing 1100, thereby tending toprevent accidental needle sticks after the initial injection and/orpotentially reducing and/or eliminating a sharps hazard.

In some embodiments, system actuator 2000 can comprise a fingertriggered, twistable, pivotable, and/or lever-operated mechanism. Forexample, system actuator 2000 can comprise a twistable handle that canscrew into gas port 2600. In some embodiments, system actuator 2000 canbe a finger trigger located on a side of the housing.

FIG. 10 is a flowchart of an embodiment of a method 10000 for operatinga medicament delivery apparatus. At activity 10100, an actuation lockfor the apparatus is released. At activity 10200, an actuating portionof the contents of a compressed gas container are released. At activity10300, via pressure provided by the released gas, a needle is extendedfrom the apparatus. At activity 10400, via pressure provided by thereleased gas, a piston applies pressure to a medicament stored in one ofa plurality of vials. At activity 10500, a frangible seal containing themedicament in the vial is burst. At activity 10600, the medicament flowsfrom the vial, through the needle, and into a patient. At activity10700, once a predetermined dose is expelled and/or injected, the needleis withdrawn from the patient and/or retracted into the pre-use boundsof the apparatus. At activity 10800, the apparatus is rendered unusablefor additional injections and/or indicated as previously utilized.

FIG. 11 is a perspective view of an embodiment of system 1000, showingactuation guard 1200 removed from housing 1100, so that actuation guard1200 no longer separates actuator bar 1300 from handheld portion 1800.Actuation guard 1200 can comprise a grippable portion 1220 that can begripped by a user to pull actuation guard 1200 away from housing 1100,thereby allowing system 1000 to be activated, such as via slappingactuator bar 1300 against a thigh of the user. Actuation guard 1200 cancomprise an actuation stick separator portion 1240, that can keepseparate actuation stick prongs 2240 when actuation guard 1200 isinstalled on housing 1100. Actuation guard 1200 can comprise a guardportion 1260 that can separate actuator bar 1300 from handheld portion1800 when system 1000 is not in use and/or when system 1000 has not beenused.

FIG. 12 is a perspective cross-sectional view taken along line B-B ofFIG. 11, and FIG. 13 is a perspective view of an embodiment of actuationstick 2200. Referring to FIGS. 12 and 13, system 1000 can comprisehousing 1100, actuation bar 1300, and system actuator 2000, which cancomprise prong squeezer 1390, actuation stick 2200, prong retainer 2100,spring 2300, upper spring retainer 2260, gas container 2400, gas port2600, and/or puncturer 2700. When actuation bar 1300 is pressed firmlyagainst a user's body, such as via slapping housing actuation baragainst the user's thigh, buttocks, and/or arm, prong squeezer 1390 canurge prong tips 2220 of prongs 2240 of actuation stick 2200 toward oneanother. Note that prong tips 2200 can have a triangular, wedge,angular, and/or frusto-conical shape. As prongs tips 2220 slide alongthe angled V-groove of prong squeezer 1390, prong catches 2230 cansubstantially lose contact with prong retainer 2100. This can allowcompressed spring 2300 to rapidly urge actuation stick 2200 and gascontainer 2400 toward puncturer 2700, which can penetrate gas port 2600,thereby allowing gas to escape from gas container 2400. Although any ofmany different types of gas containers can be utilized, an example of asuitable gas container can be obtained from Leland Limited, Inc. ofSouth Plainfield, N.J.

FIG. 14 is a cross-sectional view of an embodiment of gas ventingmechanism 8000 of system 1000 taken along line A-A of FIG. 3. System1000 can comprise handheld portion 1800, actuator bar 1300, sleeve 1500.As pistons 4440 near the limit of their travels, medicament 5200 can beexpelled along medicament path 5900, which can extend past frangibleseal 5300, through medicament channels 9200, medicament conduit 9300,and needle 6100, and into the body of a user, such as subcutaneously,intramuscularly, and/or at a depth of from approximately 0.25millimeters to approximately 20 millimeters, including all values andsubranges therebetween, such as up to 2 millimeters, greater than 5millimeters, etc.

As pistons 4440 near the limit of their travels, engagement of gasrelease actuator 9700 with gas relief valve 8200 can cause compressedspring 8300 to move valve arm such that o-ring 8400 is urged away fromits seat 8500. This movement can reveal a passage 8600, via which gascan exit gas chamber 3200 along gas exhaust path 8900, which can extendbetween sleeve inner walls 1520 and outer walls 9100 of medicamentcarrier 9000. Eventually, gas exhaust path 8900 can extend betweenhandheld portion 1800 and actuator bar 1300. Likewise, an alternativeembodiment of valve 8200, made of rubber or any other resilientmaterial, can be placed across seat 8500 to provide a seal that, oncegas release actuator 9700 interacts with valve 8200, allows valve 8200to bend or flap upwards away from seat 8500, causing the gas to escapevia passage 8600.

FIGS. 15 and 16 are schematic illustrations of an auto-injector 2002according to an embodiment of the invention in a first configuration anda second configuration, respectively. The auto-injector 2002 includes ahousing 2110, a medicament container 2262, a movable member 2312, a gasrelief valve 2328 and a compressed gas source 2412. The medicamentcontainer 2262, which can be, for example, a pre-filled cartridge, avial, an ampule or the like, is fixedly disposed within the housing 2110and defines a longitudinal axis Lm. The medicament container 2262contains a medicament 2268, such as, for example, epinephrine.

The movable member 2312 includes a proximal end portion 2316 and adistal end portion 2318. The proximal end portion 2316 includes asurface 2322 that, together with the housing 2110, defines a gas chamber2120. Said another way, the surface 2322 defines a portion of a boundaryof the gas chamber 2120. The proximal end portion 2316 defines anopening 2326 therethrough, which is in fluid communication between thegas chamber 2120 and an area outside of the gas chamber 2128. The distalend portion 2318 is movably disposed within the medicament container2262 along the longitudinal axis Lm, as shown by the arrow A. A needle2212 is coupled to the distal end 2318 of the movable member 2312. Theneedle 2212 defines a lumen (not shown) and a side opening 2215.

The gas relief valve 2328 is coupled to the movable member 2312 suchthat it can selectively allow fluid communication between the gaschamber 2120 and the area outside of the gas chamber 2128. The gasrelief valve 2328 can include, for example, a movable membrane, afrangible seal, a spring-loaded gas relief valve body or the like.

In use, when the auto-injector 2002 is actuated, the gas chamber 2120 isplaced in fluid communication with the compressed gas source 2412,thereby allowing a pressurized gas to flow into the gas chamber 2120. Inresponse to a force produced by the pressurized gas on the surface 2322of the movable member 2312, the movable member 2312 moves within thehousing 2110 and the medicament container 2262, as indicated by arrow A.As a result, as shown in FIG. 16, the needle 2212 is extended throughthe housing 2110. The movement of the movable member 2312 also forcesthe medicament 2268 through the side opening 2215 and into the lumen(not shown) defined by the needle 2212. In this manner, the medicamentinjection occurs while the needle 2212 is being extended from thehousing 2110 (i.e., while the needle 2212 is being inserted into thebody).

In use, the pressure of the pressurized gas within the gas chamber 2120can be controlled by the gas relief valve 2328. As shown in FIG. 16, thegas relief valve 2328 is actuated as indicated by the arrow B, therebyallowing pressurized gas to flow from the gas chamber 2120 to the areaoutside of the gas chamber 2128 through the opening 2326, as shown bythe arrows g. Although the gas relief valve 2328 is shown as beingactuated after substantially all of the medicament 2268 has beeninjected, in other embodiments, the gas relief valve 2328 can beactuated at any time during the injection event. For example, in someembodiments, the gas relief valve 2328 can be actuated as the injectionevent is beginning to control the rate of needle insertion and/ormedicament injection. In other embodiments, the gas relief valve 2328can be actuated at the end of the injection event to allow the needle2212 to be retracted to a position within the housing 2110. In yet otherembodiments, the gas relief valve 2328 can be actuated upon completionof the injection event to prevent residual gas from undesirably buildingup within the gas chamber 2120.

FIG. 17 is a perspective view of an auto-injector 3002 according to anembodiment of the invention in a first configuration. The auto-injector3002 includes a housing 3110 having a proximal end portion 3112 and adistal end portion 3114. The distal end portion 3114 of the housing 3110includes a protrusion 3142 to help a user grasp and retain the housing3110 when using the auto-injector 3002. Said another way, the protrusion3142 is configured to prevent the auto-injector 3002 from slipping fromthe user's grasp during use. A base 3520 is movably coupled to thedistal end portion 3114 of the housing 3110. A needle guard assembly3810 is removably coupled to the base 3520. Similarly, a safety lock3710 is removably coupled to the base 3520. To inject a medicament intothe body, the distal end portion 3114 of the housing is oriented towardsthe user such that the base 3520 is in contact with the portion of thebody where the injection is to be made. The base 3520 is then movedtowards the proximal end 3112 of the housing 3110 to actuate theauto-injector 3002. The housing 3110 also includes a transparent statuswindow 3118 (see FIG. 36) to allow a user to determine the status of theauto-injector 3002 or the medicament contained therein.

FIG. 18 is a perspective view of the auto-injector 3002 showing thehousing 3110 in phantom lines so that the components contained withinthe housing 3110 can be more clearly seen. For clarity, FIG. 18 showsthe auto-injector 3002 without the needle guard assembly 3810 and thesafety lock 3710. Similarly, FIG. 19 is a front view of theauto-injector 3002 showing the housing 3110 in phantom lines. Theauto-injector 3002 includes a medicament injector 3210 and a movablemember 3312 engaged with the medicament injector 3210, each of which aredisposed within the housing 3110. The auto-injector 3002 also includes asystem actuator 3510, a compressed gas container 3412 and a gas releasemechanism 3612.

The medicament injector 3210 includes a carrier 3250 that is movablewithin the housing 3110, a medicament container 3262 and a needle 3212.The medicament container 3262 is coupled to the carrier 3250. The needle3212 is disposed within a needle hub portion 3223 (see FIG. 22) of thecarrier to allow the needle 3212 to be placed in fluid communicationwith the medicament container 3262 during an injection event.

The movable member 3312 includes a proximal end portion 3316 and adistal end portion 3318. The proximal end portion 3316 includes asurface 3322 that, together with the housing 3110, defines a gas chamber3120. Said another way, the surface 3322 defines a portion of a boundaryof the gas chamber 3120. The distal end portion 3318 is disposed withinthe medicament container 3262. In use, the movable member 3312 movestowards the distal end portion 3114 of the housing 3110, as indicated byarrow C, in response to a force produced by a pressurized gas on thesurface 3322 of the movable member 3312. As a result, the movable member3312 and the medicament injector 3250 are moved towards the distal endportion 3114 of the housing 3110, thereby exposing the needle 3212 fromthe housing 3110. The movable member 3312 then continues to move withinthe medicament container 3262 to expel a medicament from the medicamentcontainer 3262 through the needle 3212.

The auto-injector 3002 is actuated by the system actuator 3510, which isconfigured to move the compressed gas container 3412 into contact withthe gas release mechanism 3612. The gas release mechanism 3612 puncturesa portion of the compressed gas container 3412 to release thepressurized gas contained therein into the gas chamber 3120 defined bythe housing 3110.

The system actuator 3510 includes a rod 3540, a spring 3560 and a springretainer 3570. The rod 3540 has a proximal end portion 3542 and a distalend portion 3544. The proximal end portion 3542 of the rod 3540 iscoupled to the compressed gas container 3412. The distal end portion3544 of the rod 3540 is coupled to the spring retainer 3570 by twoprojections 3548, which can be moved inwardly towards each other todecouple the rod 3540 from the spring retainer 3570, as discussed below.

The spring 3560 is disposed about the rod 3540 in a compressed statesuch that the spring 3560 is retained by the proximal end portion 3542of the rod 3540 and the spring retainer 3570. In this manner, the rod3540 is spring-loaded such that when the distal end portion 3544 of therod 3540 is decoupled from the spring retainer 3570, the force of thespring 3560 causes the rod 3540, and therefore the compressed gascontainer 3412, to move proximally as indicated by arrow D and intocontact with the gas release mechanism 3612.

The base 3520 defines an opening 3522 configured to receive a portion ofthe projections 3548 when the base is moved towards the proximal end3112 of the housing 3110, as indicated by arrow E. When the projections3548 are received within the opening 3522, they are moved togethercausing the distal end portion 3544 of the rod 3540 to be released fromthe spring retainer 3570.

As shown in FIGS. 18 and 19, the medicament injector 3210 defines alongitudinal axis Lm that is non-coaxial with the longitudinal axis Ledefined by the compressed gas container 3412. Accordingly, themedicament injector 3210, the compressed gas container 3412 and thesystem actuator 3510 are arranged within the housing 3110 such that thehousing has a substantially rectangular shape. Moreover, the non-coaxialrelationship between the medicament injector 3210 and the compressed gascontainer 3412 allows the auto-injector 3002 to be actuated bymanipulating the base 3520, which is located at the distal end portion3114 of the housing 3110.

As discussed above, the use and actuation of the auto-injector 3002includes several discrete operations. First, the auto-injector 3002 isenabled by removing the needle guard 3810 and the safety lock 3710 (seeFIGS. 20 and 21). Second, the auto-injector 3002 is actuated by movingthe base 3520 proximally towards the housing 3110. Third, when actuated,the compressed gas container 3412 engages the gas release mechanism3612, which causes the pressurized gas to be released into the gaschamber 3120 (see FIG. 31). Fourth, the pressurized gas produces a forcethat causes the movable member 3312 and the medicament injector 3210 tomove distally within the housing 3110 (see FIG. 37). The movement of themedicament injector 3210 causes the needle 3212 to extend from distalend portion 3114 of the housing 3110 and the base 3520. This operationcan be referred to as the “needle insertion” operation. Fifth, when themedicament injector 3210 has completed its movement (i.e., the needleinsertion operation is complete), the movable member 3312 continues tomove the medicament container 3262 distally within the carrier 3250. Thecontinued movement of the medicament container 3262 places the needle3212 in fluid communication with the medicament container 3262, therebyallowing the medicament to be injected (see FIG. 43). Sixth, the forcefrom the pressurized gas causes the movable member 3312 to move withinthe medicament container 3262, thereby expelling the medicament throughthe needle 3212 (see FIG. 44). This operation can be referred to as the“injection operation.” Seventh, upon completion of the injection, thepressurized gas is released from the gas chamber 3120, thereby allowingthe medicament injector 3210 and the movable member 3312 to be movedproximally within the housing. This operation can be referred to as the“retraction operation” (see FIG. 45). A detailed description of thecomponents contained in the auto-injector 3002 and how they cooperate toperform each of these operations is discussed below.

Prior to use, the auto-injector 3002 must first be enabled by firstremoving the needle guard 3810 and then removing the safety lock 3710.As illustrated by arrow G in FIG. 20, the needle guard 3810 is removedby pulling it distally. Similarly, as illustrated by arrow H in FIG. 21,the safety lock 3710 is removed by pulling it substantially normal tothe longitudinal axis Le of the compressed gas container 3412. Saidanother way, the safety lock 3710 is removed by moving it in a directionsubstantially normal to the direction that the needle guard 3810 ismoved. As described in more detail herein, the needle guard 3810 and thesafety lock 3710 are cooperatively arranged to prevent the safety lock3710 from being removed before the needle guard 3810 has been removed.Such an arrangement prevents the auto-injector 3002 from being actuatedwhile the needle guard 3810 is in place.

As illustrated in FIG. 22, the needle guard 3810 includes a sheath 3820and a sheath retainer 3840. The sheath 3820 has a proximal end portion3822 and a distal end portion 3824 and defines an opening 3826configured to receive a portion of the needle 3212 when the needle guard3810 is in a first (or installed) position. The sheath 3820 furtherdefines a recessed portion 3828 within the opening 3826 that engages acorresponding protrusion 3238 defined by an outer surface 3236 of theneedle hub 3223. In this manner, when the needle guard 3810 is in itsfirst position, the sheath 3820 is removably coupled to the needle hub3223. In some embodiments, the recessed portion 3828 and the protrusion3238 form a seal that is resistant to microbial penetration.

The sheath retainer 3840 has a proximal portion 3842 and a distalportion 3844. The proximal portion 3842 of the sheath retainer 3840includes a protrusion 3856 that engages a corresponding recess 3526 inthe base 3520 (see FIG. 28) to removably couple the sheath retainer 3840to the base 3520. The distal portion 3844 of the sheath retainer 3840defines an opening 3846 through which the distal end portion 3824 of thesheath 3820 is disposed. The distal portion 3844 of the sheath retainer3840 includes a series of retaining tabs 3852 that engage the distal endportion 3824 of the sheath 3820 to couple the sheath 3820 to the sheathretainer 3840. In this manner, when the sheath retainer 3840 is moveddistally away from the base 3520 into a second (or removed) position, asshown in FIG. 20, the sheath 3820 is removed from the needle 3412.Moreover, this arrangement allows the sheath 3820 to be disposed aboutthe needle 3412 independently from when the sheath retainer 3840 iscoupled to the sheath 3820. As such, the two-piece construction of theneedle guard provides flexibility during manufacturing. The distalportion 3844 of the sheath retainer 3840 also includes a protrusion 3848to aid the user when grasping the needle guard 3810.

When the needle guard 3810 is in its first position, the sheath retainer3840 is disposed within a recess 3720 defined by one of the extendedportions 3716 of the safety lock 3710 (see FIG. 25). This arrangementprevents the safety lock 3710 from being removed when the needle guard3810 is in its first position, which in turn, prevents the auto-injector3002 from being actuated when the needle guard 3810 is in its firstposition.

The outer surface of the sheath retainer 3840 includes an indicia 3850to instruct the user in operating the auto-injector 3002. As shown inFIG. 21, the indicia 3850 includes a numeral to indicate the order ofoperation and an arrow to indicate the direction in which the needleguard 3810 should be moved. In some embodiments, the indicia 3850 caninclude different colors, detailed instructions or any other suitableindicia to instruct the user. In other embodiments, the indicia 3850 canprotrude from the sheath retainer 3840 to aid the user when grasping theneedle guard 3810.

In some embodiments, the sheath 3820 can be constructed from anysuitable material, such as, for example polypropylene, rubber or anyother elastomer. In some embodiments, the sheath 3820 can be constructedfrom a rigid material to reduce the likelihood of needle sticks duringthe manufacturing process. In other embodiments, the sheath 3820 can beconstructed from a flexible material.

After the needle guard 3810 is removed, the user must then remove thesafety lock 3710, as indicated in FIG. 21. As shown in FIG. 25, thesafety lock 3710 is a U-shaped member having a first end 3712 and asecond end 3714. The second end 3714 of the safety lock 3710 includestwo extended portions 3716, each of which includes an inwardly facingprotrusion 3718. When the safety lock 3710 is in its first (or locked)position, the extended portions 3716 extend around a portion of the base3520 to space the base 3520 apart from the distal end portion 3114 ofthe housing 3110. As shown in FIG. 26, the protrusions 3718 areconfigured engage a portion of the base 3520 to removably couple thesafety lock 3710 in its first position.

One of the extended portions 3716 defines a recess 3720 that receivesthe sheath retainer 3840 when the needle guard 3810 is in its firstposition, as discussed above. Although only one extended portion 3716 isshown as including a recess 3720, in some embodiments both extendedportions 3716 can include a recess 3720 to receive the sheath retainer3840. In other embodiments, the safety lock 3710 can be engaged with theneedle guard 3810 to prevent movement of the safety lock 3710 when theneedle guard 3810 is in place in any suitable manner. For example, insome embodiments, the sheath retainer can include protrusions that arereceived within corresponding openings defined by the safety lock. Inother embodiments, the safety lock can include protrusions that arereceived within corresponding openings defined by the sheath retainer.

The first end 3712 of the safety lock 3710 includes a locking protrusion3722 that extends inwardly. As shown in FIG. 26, when the safety lock3710 is in its first position, the locking protrusion 3722 extendsbetween the projections 3548 of the rod 3540 and obstructs the opening3522 of the base 3520. In this manner, when the safety lock 3710 is inits first position, the base 3520 cannot be moved proximally to allowthe projections 3548 to be received within the opening 3522. Thearrangement of the locking protrusion 3722 also prevents the projections3548 from being moved inwardly towards each other. Accordingly, when thesafety lock 3710 is in its first position, the auto-injector 3002 cannotbe actuated.

The outer surface 3724 of the first end 3712 of the safety lock 3710includes a series of ridges 3726 to allow the user to more easily gripthe safety lock 3710. The outer surface 3724 of the first end 3712 ofthe safety lock 3710 also includes an indicia 3728 to instruct the userin operating the auto-injector 3002. As shown in FIG. 25, the indicia3728 includes a numeral to indicate the order of operation and an arrowto indicate the direction in which the safety lock 3710 should be moved.In some embodiments, the indicia 3728 can include different colors,detailed instructions or any other suitable indicia to instruct theuser. In other embodiments, the indicia 3728 can protrude from thesafety lock 3710 to aid the user when grasping the safety lock 3710.

After being enabled, the auto-injector 3002 can then be actuated bymoving the base 3520 proximally towards the housing 3110, as indicatedby arrow I in FIG. 27. As shown in FIGS. 28 and 36, the base 3520defines two openings 3536 that receive corresponding attachmentprotrusions 3150 disposed on the distal end portion 3114 of the housing3110. In this manner, the movement and/or alignment of the base 3520relative to the housing 3110 is guided by the attachment protrusions3150 and the openings 3536 (see FIG. 36).

Each attachment protrusion 3150 is secured within its correspondingopening 3536 by a lock washer 3534. The lock washers 3534 each define anopening 3535 that receives a portion of the attachment protrusion 3150.The lock washers 3534 are disposed within slots 3533 defined by the base3520 so that the openings 3535 are aligned with the attachmentprotrusions 3150. The openings 3535 are configured to allow the lockwashers 3534 to move proximally relative to the attachment protrusions3150, but to prevent movement of the lock washers 3534 distally relativeto the attachment protrusions 3150. In this manner, when the attachmentprotrusions 3150 are disposed within the openings 3535 of the lockwashers 3534, the base 3520 becomes fixedly coupled to the housing 3110.Moreover, after the base 3520 is moved proximally relative to thehousing 3110, the lock washers 3534 prevent the base 3520 from returningto its initial position. Said another way, the arrangement of the lockwashers 3534 prevents the base 3520 from being “kicked back” after theauto-injector 3002 has been actuated.

The base 3520 also defines a needle opening 3532, a recess 3526 and tworetraction spring pockets 3531. The needle opening 3532 receives aportion of the needle guard 3810 when the needle guard is in its firstposition. Additionally, when the auto-injector is in its thirdconfiguration (see FIG. 37), the needle 3212 extends through the needleopening 3532. As described above, the recess 3526 receives thecorresponding protrusion 3856 on the sheath retainer 3840 to removablycouple the needle guard 3810 to the base 3520. As will be described inmore detail herein, the retraction spring pockets 3531 receive a portionof the retraction springs 3350.

As shown in FIG. 28, the base 3520 includes two opposing taperedsurfaces 3524 that define an opening 3522 configured to receive acorresponding tapered surface 3550 of the projections 3548 when the baseis moved proximally towards the housing 3110. When the projections 3548are received within the tapered opening 3522, they are moved together asindicated by arrows J in FIG. 27. The inward movement of the projections3548 causes the rod 3540 to become disengaged from the spring retainer3570, thereby allowing the rod 3540 to be moved proximally along itslongitudinal axis as the spring 3560 expands. A more detaileddescription of the components included in the system actuator 3510 isprovided below with reference to FIGS. 29 and 30.

The system actuator 3510 includes a rod 3540, a spring 3560 disposedabout the rod 3540 and a spring retainer 3570. As described in moredetail herein, the spring retainer 3570 retains both the spring 3560 andthe rod 3540. The spring retainer 3570 includes a first surface 3572, asecond surface 3574 and a series of outwardly extending engagement tabs3576. The spring retainer 3570 is disposed within the gas containeropening 3124 defined by the housing 3110 (see FIG. 36) such that theengagement tabs 3576 engage the interior surface 3123 of the housing3110 to produce an interference fit. In this manner, the spring retainer3570 is fixedly disposed within the housing 3110.

The rod 3540 has a proximal end portion 3542 and a distal end portion3544. The distal end portion 3544 of the rod 3540 includes twoextensions 3552 disposed apart from each other to define an opening 3554therebetween. Each extension 3552 includes a projection 3548 having atapered surface 3550 and an engagement surface 3549. When the rod 3540is in its first (or engaged) position, the engagement surfaces 3549engage the second surface 3574 of the spring retainer 3570 to preventthe rod 3540 from moving proximally along its longitudinal axis. Asdescribed above, when the base 3520 is moved proximally towards thehousing 3110, the tapered surfaces 3550 of the projections 3548cooperate with the corresponding tapered surfaces 3524 of the base 3520to move the extensions 3552 inwardly towards each other. The inwardmotion of the extensions 3552 causes the engagement surfaces 3549 tobecome disengaged from the second surface 3574 of the spring retainer3570, thereby allowing the rod 3540 to move between its first positionto a second (or actuated) position.

The proximal end portion 3542 of the rod 3540 includes a retentionportion 3545 having a first surface 3547 and a second surface 3546. Thefirst surface 3547 of the retention portion 3545 engages the distalportion 3416 of the compressed gas container 3412. The second surface3546 of the retention portion 3545 engages a proximal end 3562 of thespring 3560. Similarly, the first surface 3572 of the spring retainer3570 engages a distal end 3564 of the spring 3560. In this manner, whenthe rod 3540 is in its first position, the spring 3560 can be compressedbetween the spring retainer 3570 and the retention portion 3545 of therod 3540. Accordingly, when the rod 3540 is disengaged from the springretainer 3570, the force imparted by the spring 3560 on the retentionportion 3545 of the rod 3540 causes the rod 3540 to move proximally intoits second position.

The proximal end portion 3542 of the rod 3540 is coupled to thecompressed gas container 3412 by a connector 3580, which is secured tothe distal end portion 3416 of the compressed gas container 3412 by asecuring member 3588. The connector 3580 includes a proximal end portion3582 and a distal end portion 3584. The distal end portion 3584 of theconnector 3580 is disposed within the opening 3554 defined between theextensions 3552. In this manner, the connector 3580 is retained by theproximal end portion 3542 of the rod 3540. As will be described in moredetail, the distal end portion 3584 of the connector 3580 includeslocking tabs 3587.

The proximal end portion 3582 of the connector 3580 includes engagementportions 3586 that engage the distal end portion 3416 of the compressedgas container 3412. The engagement portions 3586 are coupled to thecompressed gas container 3412 by the securing member 3588, which can be,for example, a shrink wrap, an elastic band or the like. In otherembodiments, the engagement portions 3586 can produce an interferencefit with the compressed gas container 3412, thereby eliminating the needfor a securing member 3588.

Because the rod 3540 is coupled to the compressed gas container 3412,when the rod 3540 is moved from its first (engaged) position to itssecond (actuated) position, the compressed gas container 3412 is movedproximally within the housing 3110 into engagement with the gas releasemechanism 3612. FIG. 31 shows the auto-injector in a secondconfiguration, in which the compressed gas container 3412 is engagedwith the gas release mechanism 3612. When in the second configuration,the compressed gas contained within the compressed gas container 3412 isreleased to actuate the medicament injector 3210. A more detaileddescription of the gas release process is provided below with referenceto FIGS. 32 through 36.

FIG. 32 shows an exploded view of the system actuator 3510, thecompressed gas container 3412 and the gas release mechanism 3612, eachof which are disposed within the gas container opening 3124 defined bythe housing 3110 (see FIG. 36). As shown, the compressed gas container3412, the system actuator 3510 and the gas release mechanism 3612 arearranged substantially coaxial with each other. As previously discussed,when the auto-injector 3002 is actuated, the compressed gas container3412 is moved proximally within the gas container opening 3124 definedby the housing 3110, as indicated by the arrow K in FIG. 32, until theproximal end 3414 of the compressed gas container 3412 engages the gasrelease mechanism 3612.

As shown in FIGS. 33 and 34, the gas release mechanism 3612 includes acap 3630 and a puncturing element 3620 coupled to and disposed withinthe cap 3630. The puncturing element has a proximal end 3622 and adistal end 3624. The distal end 3624 of the puncturing element 3620defines a sharp point 3626 configured to puncture the proximal end 3414of the compressed gas container 3412. The puncturing element 3620defines an opening 3627 extending from its distal end 3624 to itsproximal end 3622.

The cap 3630 has a proximal end 3632, an outer surface 3635 and an innersurface 3636. The inner surface 3636 of the cap 3630 defines an opening3634 that receives the proximal end 3414 of the compressed gas container3412 when the auto-injector 3002 is in its second configuration. Theproximal end 3632 of the cap 3630 defines an opening 3638 therethroughand a channel 3640 in fluid communication with the opening 3638. Theopening 3638 receives the proximal end 3622 of the puncturing element3620 to couple the puncturing element 3620 to the cap 3630. Thepuncturing element 3620 is disposed within the cap 3630 such that whenthe compressed gas container 3412 is moved into the opening 3634, thedistal end 3624 of the puncturing element 3620 punctures the proximalend 3414 of the compressed gas container 3412.

The cap 3630 is disposed within the gas container opening 3124 such thatthe outer surface 3635 of the cap 3630 engages the inner surface 3123 ofthe housing 3110. In some embodiments, the outer surface 3635 of the cap3630 can be sized to produce an interference fit with the inner surface3123 of the housing 3110. In other embodiments, the cap 3630 can befixedly coupled within the gas container opening 3124 using an adhesiveor any other suitable attachment mechanism.

The cap 3630 is oriented within the gas container opening 3124 so thatthe channel 3640 is aligned with and in fluid communication with the gaspassageway 3126 defined by the housing 3110. Moreover, when oriented inthis manner, the protrusion 3642 on the proximal end 3632 of the cap3630 obstructs a portion of the gas passageway 3126, which can bemanufactured as a through-hole, to fluidically isolate the gaspassageway 3126 from an area outside of the housing 3110. After theproximal end 3414 of the compressed gas container 3412 has beenpunctured, pressurized gas flows from the compressed gas container 3412into the gas passageway 3126 through the opening 3627 defined by thepuncturing element 3620 and the channel 3640 defined by the proximal end3632 of the cap 3630.

The inner surface 3636 of the cap 3630 is configured to hermeticallyseal the proximal end 3414 of the compressed gas container 3412 withinthe opening 3638. This arrangement prevents pressurized gas from leakingaround the compressed gas container 3412 to an area outside of thehousing 3110 after the proximal end 3414 of the compressed gas container3412 has been punctured. In some embodiments, the inner surface 3636 issized to produce an interference fit with the compressed gas container3412. In other embodiments, the cap 3630 includes a separate sealingmember, such as, for example, an o-ring, to seal the proximal end 3414of the compressed gas container 3412 within the opening 3638.

After the compressed gas container 3412 is moved into engagement withthe gas release mechanism 3612, the position of the compressed gascontainer 3412 within the gas container opening 3124 is maintained bythe locking tabs 3587 on the connector 3580. As shown in FIG. 29, eachlocking tab 3587 includes a pointed portion that is angled outwardlyfrom the connector 3580. This arrangement allows the connector 3580 tomove proximally within the gas container opening 3124 of the housing3110, but prevents the connector 3580 from moving distally within thegas container opening 3124 of the housing 3110. Said another way, thearrangement of the locking tabs 3587 prevents the compressed gascontainer 3412 from being “kicked back” when exposed to the forceproduced by the pressurized gas as the pressurized gas is released.

As previously discussed, the pressurized gas released from thecompressed gas container 3412 produces a force on the boundary of thegas chamber 3120, including the surface 3322 of the movable member 3312.This force causes the movable member 3312 and the medicament injector3210 move together distally within the housing 3110, as shown by arrowL, placing the auto-injector 3002 in a third configuration, as shown inFIG. 37. When in the third configuration, the distal end 3214 of theneedle 3212 is disposed through the opening 3532 defined by the base3520 to an area outside of the auto-injector 3002. Moreover, as shown inFIG. 38, when the auto-injector 3002 is in the third configuration, theproximal end 3216 of the needle 3212 remains spaced apart from thedistal end 3266 of the medicament container 3210, ensuring that theneedle 3212 remains fluidically isolated from the medicament container3210. In this manner, the needle 3212 can be inserted into a patient asthe auto-injector 3002 moves between its second configuration (FIG. 31)and its third configuration (FIG. 37) without injecting the medicamentuntil after insertion is completed. A more detailed description of themedicament injector 3210 and the movable member 3312 is provided belowwith reference to FIGS. 37 through 42.

As previously described, the medicament injector 3210 includes a carrier3250, a medicament container 3262 and a needle 3212. The carrier 3250has a lower portion 3222 and an upper portion 3252. The lower portion3222 of the carrier 3250 includes a needle hub 3223, which contains theneedle 3212. The lower portion 3222 of the carrier 3250 also defines anopening 3224 configured to receive a distal portion 3266 the medicamentcontainer 3262. As shown in FIG. 39, the needle 3212 is coupled to theneedle hub 3223 such that the proximal end 3216 of the needle 3212 isdisposed within the opening 3224 and the distal end 3214 of the needle3212 extends distally outside of the needle hub 3223.

The inner surface 3228 of the lower portion 3222 defining the opening3224 includes a protrusion 3226. The protrusion 3226 is configured toengage a corresponding recess 3272 defined by a sealing cap 3270disposed at the distal portion 3266 of the medicament container 3262(see FIG. 42) to secure the medicament container 3262 within the opening3224 such that the proximal end 3216 of the needle 3212 is spaced apartfrom the distal end 3266 of the medicament container 3210. Theprotrusion 3226 and the recess 3272 are configured such that theprotrusion 3226 will become disengaged from the recess 3272 when theforce applied exceeds a predetermined value. Said another way, theprotrusion 3226 and the recess 3272 collectively form a removablesnap-fit that allows the medicament container 3262 to be moved withinthe opening 3224 when the force applied to the medicament container 3262exceeds a predetermined value. This arrangement ensures that the needle3212 remains fluidically isolated from the medicament container 3262during the insertion operation.

The outer surface 3236 of the lower portion 3222 includes a protrusion3238. As previously described, the protrusion 3238 is configured toengage a corresponding recess portion 3828 within the opening 3826 ofthe sheath 3820 (see FIG. 23) to removably couple the sheath 3820 to theneedle hub 3223.

The lower portion 3222 of the carrier 3250 also defines two retractionspring pockets 3242 each receiving the proximal end 3352 of a retractionspring 3350. As previously discussed, the distal end 3354 of eachretraction spring 3350 is retained within the retraction spring pockets3531 defined by the base 3520. As shown in FIG. 38, when the carrier3250 moves distally within the housing 3110, the retraction springs 3350are compressed and therefore bias the carrier 3250 towards the proximalportion 3112 of the housing 3110.

The upper portion 3252 of the carrier 3250 defines an opening 3256configured to receive a proximal portion 3264 of the medicamentcontainer 3262 and includes two valve actuators 3254. As described inmore detail herein, the valve actuators 3254 are configured to engage agas relief valve 3328 to allow the pressurized gas contained within thegas chamber 3120 to escape when the injection event is complete.

The upper portion 3252 of the carrier 3250 defines four gas reliefpassageways 3258. Similarly, the lower portion 3222 of the carrier 3250defines four gas relief passageways 3244. When the pressurized gas isreleased from the gas chamber 3120, the gas relief passageways 3258,3244 provide a fluid path to allow the pressurized gas to flow from thegas chamber 3120 to an area outside of the housing 3110.

As described above, the movable member 3312 includes a proximal endportion 3316 and a distal end portion 3318. The distal end portion 3318includes a piston 3324 disposed within the proximal portion 3264 of themedicament container 3262, such that the piston engages a plunger 3284contained within the medicament container 3262, as shown in FIG. 42.

The proximal end portion 3316 includes a surface 3322 that defines aportion of a boundary of the gas chamber 3120. As shown in FIG. 41, theproximal end portion 3316 defines two openings 3326 therethrough, eachof which are in fluid communication between the gas chamber 3120 and theinterior of the housing 3110 outside the gas chamber 3120. The proximalend portion 3316 further defines a slot 3330 that receives a gas reliefvalve 3328, which can be, for example, a flexible rubber member. The gasrelief valve 3328 is positioned within the slot 3330 and adjacent theopenings 3326 to selectively allow fluid communication between the gaschamber 3120 and the area outside the gas chamber 3120 through theopenings 3326. The operation of the gas relief valve 3328 is discussedin more detail herein.

The proximal end portion 3316 of the movable member 3312 also includes aseal 3314 that engages a portion the inner surface 3122 of the housing3110 (see FIG. 36) to fluidically isolate the gas chamber 3120. Althoughthe seal 3314 is shown as being an o-ring seal, in some embodiments, theseal need not be a separate component, but can rather be a portion ofthe proximal end portion 3316 of the movable member 3312.

When the needle insertion operation is completed, the lower portion 3222of the carrier 3250 engages the base 3520, preventing further distalmovement of the carrier 3250 within the housing. Because the distalmotion of the carrier 3250 is opposed, the force exerted by thepressurized gas on the surface 3322 of the movable member 3312 increasesuntil the protrusion 3226 of the lower portion 3222 of the carrier 3250and the recess 3272 defined by sealing cap 3270 of the medicamentcontainer 3262 become disengaged. Accordingly, the medicament container3262 to moves distally relative to the carrier 3250, placing theauto-injector 3002 in a fourth configuration, as shown in FIG. 43. Whenmoving between the third configuration (FIG. 38) and the fourthconfiguration (FIG. 43), the proximal end 3216 of the needle 3212pierces the sealing cap 3270 and the liner 3271 disposed at the distalportion 3266 of the medicament container 3262. As such, when in thefourth configuration, the proximal end 3216 of the needle 3212 is influid communication with the medicament container 3262, thereby allowingthe medicament to be injected.

Once the needle 3212 is in fluid communication with the medicamentcontainer 3262, the force from the pressurized gas causes the piston3324 of the movable member 3312 to move the plunger 3284 within themedicament container 3262, as shown by arrow M, thereby expelling themedicament through the needle 3212. The piston 3324 and the plunger 3284move a predetermined distance within the medicament container 3262,placing the auto-injector 3002 in a fifth configuration, as shown inFIG. 44. When the auto-injector 3002 is in the fifth configuration, theinjection of medicament is complete.

When the auto-injector 3002 is in its fifth configuration, proximalportion 3316 of the movable member 3312 is in contact with the upperportion 3252 of the carrier 3250, thereby preventing further movement ofthe piston 3324 within the medicament container 3262. In this manner,the distance through which the piston 3324 travels, and therefore theamount of medicament injected, can be controlled.

Additionally, when the auto-injector 3002 is in its fifth configuration,the valve actuators 3254 are disposed within the openings 3326 such thatthe valve actuators 3254 displace the gas relief valve 3328.Accordingly, the pressurized gas contained within the gas chamber 3120can flow from the gas chamber 3120 to the area within the housing 3310outside of the gas chamber 3310. As previously discussed, the gas reliefpassageways 3258, 3244 provide a fluid path to allow the pressurized gasto flow from the gas chamber 3120, through the opening 3532 defined bythe base 3520 and to an area outside of the housing 3110.

When the pressurized gas flows out of the gas chamber 3120, the pressureexerted on the surface 3322 of the movable member 3312 decreases.Accordingly, the force exerted by the retraction springs 3350 issufficient to move the medicament injector 3210 and the movable member3312 proximally within the housing 3110, as shown by arrow N, into asixth (or retracted) configuration as shown in FIG. 45. Because themedicament injector 3210 and the movable member 3312 move together, thevalve actuators 3254 remain disposed within the openings 3326 as theauto-injector 3002 moves into the sixth configuration. In this manner,the gas relief valve 3328 remains displaced and the openings 3326 remainin fluid communication with the gas chamber 3120 and the area within thehousing 3310 outside of the gas chamber 3310 independent of the positionof the movable member 3312. Such an arrangement ensures that all of thepressurized gas flows out of the gas chamber 3120, thereby ensuring thatthe medicament injector 3210 and the movable member 3312 return to thesixth configuration and do not oscillate between the sixth configurationand the fifth configuration, which could lead to the needle 3212 notbeing fully retracted into the housing 3110.

Although the auto-injector 3002 has been shown and described having ahousing 3110 having a substantially rectangular shape, in someembodiments, an auto-injector can have a housing having any shape. Insome embodiments, for example, an auto-injector can have a substantiallycylindrical shape. In other embodiments, for example, the auto-injectorcan have an irregular and/or asymmetrical shape.

Certain components of the auto-injector 3002 are shown and described asbeing coupled together via protrusions and mating recesses. Theprotrusions and/or recesses can be disposed on any of the components tobe coupled together and need not be limited to only a certain component.For example, the base 3520 is shown as defining two openings 3536 thatreceive corresponding attachment protrusions 3150 on the distal endportion 3114 of the housing 3110. In some embodiments, however, theprotrusions can be disposed on the base and the mating recesses can bedefined by the distal end portion of the housing. In other embodiments,two or more components can be coupled together in any suitable way,which need not include protrusions and mating recesses. For example, insome embodiments, two or more components can be coupled together viamating shoulders, clips, adhesive and the like.

Similarly, although certain components of the auto-injector 3002 areshown and described as being constructed from multiple separatecomponents, in some embodiments, such components can be monolithicallyconstructed. For example, the carrier 3250 is shown and described asincluding an upper portion 3252 and a lower portion 3222 that areconstructed separately and then coupled together. In other embodiments,a carrier can be constructed monolithically.

Although the base 3520 of the auto-injector 3002 has been shown anddescribed covering almost the entire distal end portion 3114 of thehousing 3110, in some embodiments, a base configured to actuate theauto-injector can be disposed about only a portion of the distal end ofthe housing. For example, in some embodiments, an auto-injector caninclude a button extending from the distal end portion of the housingconfigured to engage and release the system actuator.

Although the rod 3540 is shown and described as being an elongatedmember that is released by being elastically deformed, in someembodiments, a rod can be of any suitable shape and in any suitableorientation within the housing. Moreover, in some embodiments, a rod canbe released by being plastically deformed. For example, in someembodiments, a rod can be disposed along an axis that is offset from thelongitudinal axis of the energy storage member. In some embodiments, therod can be configured to break upon actuation.

Although the gas release mechanism 3612 is shown and described asincluding a puncturing element 3620 to puncture a portion of thecompressed gas container 3262, the gas release mechanism 3612 need notinclude a puncturing element 3620. For example, in some embodiments, thegas release mechanism can include an actuator configured to actuate avalve that controls the flow of gas out of the compressed gas container.For example, in some embodiments, a compressed gas container can includea spring loaded check ball and the gas release mechanism can include anactuator configured to engage and depress the check ball to releasepressurized gas from the compressed gas container.

Although the auto-injector 3002 is shown and described as having sixdifferent configurations that are different from each other, in someembodiments, certain configuration of an auto-injector can be the sameas another configuration. For example, in some embodiments, a“pre-actuation configuration can be the same as a “retracted”configuration. In other embodiments, any of the functions describedabove can be accomplished when an auto-injector is moved between anynumber of different configurations.

Although the compressed gas container 3412 is shown and described aboveas a single-use compressed gas container disposed within the housing3110, in some embodiments, a compressed gas container can be a multi-usecontainer. Moreover, the compressed gas container need not be containedwithin the housing. For example, in some embodiments, the compressed gascontainer can be a container disposed outside of the housing.Additionally, the compressed gas container can be any source ofpressurized gas. For example, in some embodiments, the compressed gassource can be a container having two or more chemicals formulated toproduce a pressurized gas when mixed. In other embodiments, thecompressed gas source can be any reservoir that can supply a gas atpressures greater than atmospheric pressure.

Although the auto-injectors shown and described above include a gasrelief valve coupled to a movable member and configured to selectivelyallow fluid flow through an opening defined by the movable member, insome embodiments, the gas relief valve and/or the opening can bedisposed apart from the movable member. For example, FIGS. 46-48 areschematic illustrations of an auto-injector 4002 in a firstconfiguration, a second configuration and a third configuration,respectively. The auto-injector 4002 includes a housing 4110, amedicament container 4262, a movable member 4312, a gas relief valve4328 and a compressed gas source 4412.

The medicament container 4262 is movably disposed within the housing4110 and defines a longitudinal axis Lm. An injection member 4212 iscoupled to and can be placed in fluid communication with the medicamentcontainer 4262. The injection member 4212 can be, for example, a needle,a nozzle or the like. As illustrated, the medicament container 4262 canbe moved along its longitudinal axis Lm between a first position (FIG.46) and a second position (FIG. 47). When the medicament container 4262is in its first (or retracted) position, the injection member 4212 isdisposed within the housing 4110. When the medicament container 4262 isin the second (or advanced) position (FIG. 47), a portion of theinjection member 4212 is disposed outside of the housing 4110 and isplaced in fluid communication with the medicament container 4262. Inthis manner, when the medicament container 4262 is in the second (oradvanced) position, a medicament 4268 can be conveyed via the injectionmember 4212 from the medicament container 4262 into a body of a patient.In some embodiments, the injection member 4212 is disposed adjacent anouter surface of the housing, but can be able to deliver a medicamentinto a body.

The movable member 4312 includes a proximal end portion 4316 and adistal end portion 4318. As described above, the proximal end portion4316 includes a surface 4322 that, together with the housing 4110,defines a gas chamber 4120. The proximal end portion 4316 also includesa seal 4314 that engages a portion of the housing to fluidically isolatethe gas chamber 4120 from an area 4128 within the housing 4110. Thedistal end portion 4318 is disposed within and movable within themedicament container 4262 along the longitudinal axis Lm.

The housing 4110 includes a side wall 4122 that defines a portion of thegas chamber 4120. The side wall 4122 defines an opening 4152, which canbe in fluid communication between the gas chamber 4120 and an areaoutside of the housing 4129. The gas relief valve 4328 is coupled to thehousing 4110 such that it can selectively allow fluid communicationbetween the gas chamber 4120 and the area outside of the housing 4129through the opening 4152.

Similar to the operation described above, when the auto-injector 4002 isactuated, a pressurized gas flows from the compressed gas source 4412into the gas chamber 4120. In response to a force produced by thepressurized gas, the movable member 4312 moves within the housing 4110thereby placing the medicament container 4262 in its second position(FIG. 47). The movable member 4312 continues to move within themedicament container 4262, as indicated by arrow P in FIG. 48, to expela medicament 4268 through the injection member 4212. When the medicamentcontainer 4262 is in is second position, the gas relief valve 4328 isactuated as indicated by the arrow Q in FIG. 48, thereby allowingpressurized gas to flow from the gas chamber 4120 to the area outside ofthe housing 4129 through the opening 4152. The gas relief valve 4328 canbe actuated by any suitable valve actuator. For example, in someembodiments the auto-injector 4002 can include a mechanical valveactuator (not shown) that the user manually depresses to actuate thevalve 4328.

FIGS. 49 and 50 are schematic illustrations of an auto-injector 5002 ina first configuration and a second configuration, respectively. Theauto-injector 5002 includes a housing 5110, a medicament container 5262,a movable member 5312, a compressed gas source 5412 and a gas releaseassembly 5325. As described above, the medicament container 5262 isfixedly disposed within the housing 5110 and defines a longitudinal axisLm.

The movable member 5312 includes a proximal end portion 5316 and adistal end portion 5318. The proximal end portion 5316 includes asurface 5322 that defines a portion of a boundary of a gas chamber 5120.The distal end portion 5318 is movably disposed within the medicamentcontainer 5262 along the longitudinal axis Lm, as shown by the arrow S.A needle 5212 defining a lumen and a side opening (not shown) is coupledto the distal end 5318 of the movable member 5312.

The gas release assembly 5325 includes a gas relief valve 5328, aflexible member 5329 and an opening 5152. The opening 5152 is defined bya side wall 5122 of the housing 5110 that defines a portion of the gaschamber 5120. In this manner, the opening 5152 can provide fluidcommunication between the gas chamber 5120 and an area outside of thehousing 5129. The housing 5110 includes a covering portion 5154 disposedadjacent the opening 5152 to prevent the opening 5152 from becomingobstructed, to prevent the gas relief valve 5328 from beinginadvertently actuated or the like.

The gas relief valve 5328 is removably disposed within the opening 5152and has a first configuration (FIG. 49) and a second configuration (FIG.50). When the gas relief valve 5328 is in its first configuration, it isdisposed within the opening 5152 such that it fluidically isolates thegas chamber 5120 from the area outside of the housing 5129. When the gasrelief valve 5328 is in its second configuration, it is removed from theopening 5152, thereby placing the gas chamber 5120 in fluidcommunication with the area outside of the housing 5129. The gas reliefvalve 5328 can be, for example, a rigid member that is press fit withinthe opening 5152, a flexible member that is secured about the opening5152 by an adhesive, a frangible sealing member or any other suitabledevice that can be removably disposed within and/or about the opening5152.

The gas relief valve 5328 is coupled to the movable member 5312 by aflexible member 5329. By coupling the gas relief valve 5328 to themovable member 5312, the gas relief valve 5328 can be moved from itsfirst configuration to its second configuration when the movable member5312 reaches a predetermined position within the housing 5110. Moreover,after the gas relief valve 5328 has been actuated, this arrangementallows the gas relief valve 5328 to remain in its second configurationindependent of the position of the movable member 5312. The flexiblemember 5329 can be any suitable structure for coupling the gas reliefvalve 5328 to the movable member 5312. For example, the flexible membercan be a string, an elastic member, a biasing member or the like.

In use, when the auto-injector 5002 is actuated, a pressurized gas flowsfrom the compressed gas source 5412 into the gas chamber 5120. Inresponse to a force produced by the pressurized gas, the movable member5312 moves within the housing 5110 and the medicament container 5262. Asa result, the needle 5212 is extended through the housing 5110 and themedicament is injected via the needle 5212. When the movable member 5312reaches a predetermined position within the housing 5110, the flexiblemember 5329 moves the gas relief valve 5328 into its secondconfiguration, as shown by the arrow T in FIG. 50. In this manner,pressurized gas flows from the gas chamber 5120 to the area outside ofthe housing 5129 through the opening 5152, as shown by the arrows g. Asthe pressure in the gas chamber 5120 is reduced, the movable member 5312and the needle 5212 can be retracted into the housing 5110, as describedabove.

Although the auto-injector 3002 is shown and described as including agas relief valve 3328 that is automatically actuated by a valve actuator3254 disposed on the carrier 3250, in some embodiments, an auto-injectorcan include a gas relief valve that is automatically actuated by anytype of valve actuator. For example, in some embodiments, anauto-injector can include a gas relief valve that is actuatedelectronically, magnetically, hydraulically, pneumatically or by anyother suitable mechanism. In other embodiments, an auto-injector caninclude a gas relief valve that is manually actuated by the user, forexample, by a push button that extends within the housing.

Although the auto-injector 3002 shown and described above includes avalve actuator 3254 coupled to the carrier 3250, in some embodiments, anauto-injector can include a valve actuator disposed anywhere within theauto-injector. For example, FIGS. 51-53 are schematic illustrations ofan auto-injector 6002 in a first configuration, a second configurationand a third configuration, respectively, in which a valve actuator 6254is coupled to a housing 6110. The auto-injector 6002 includes thehousing 6110, a medicament container 6262, a movable member 6312, a gasrelief valve 6328, the valve actuator 6254 and a compressed gas source6412. As described above, the medicament container 6262 is fixedlydisposed within the housing 6110 and defines a longitudinal axis Lm.

The movable member 6312 includes a proximal end portion 6316 and adistal end portion 6318. The proximal end portion 6316 includes asurface 6322 that defines a portion of a boundary of a gas chamber 6120.The proximal end portion 6316 defines an opening 6326 therethrough,which can be selectively placed in fluid communication between the gaschamber 6120 and an area outside of the gas chamber 6128. The distal endportion 6318 is movably disposed within the medicament container 6262along the longitudinal axis Lm, as shown by the arrow U. A needle 6212defining a lumen and a side opening (not shown) is coupled to the distalend 6318 of the movable member 6312.

A biasing member 6350 extends between the proximal end portion 6316 ofthe movable member 6312 and the housing 6110. The biasing member, whichcan be, for example, a spring, an elastic member or the like, isconfigured to bias the movable member 6312 towards the proximal portion6112 of the housing 6110.

The gas relief valve 6328 is coupled to the movable member 6312 adjacentthe opening 6326 and has a first configuration (FIG. 51) and a secondconfiguration (FIGS. 52-53). When the gas relief valve 6328 is in itsfirst configuration, it is disposed within the opening 6326 such that itfluidically isolates the gas chamber 6120 from the area outside of thegas chamber 6128. When the gas relief valve 6328 is in its secondconfiguration, it is moved or punctured, thereby placing the gas chamber6120 in fluid communication with the area outside of the gas chamber6128.

The valve actuator 6254 has a proximal end 6253 and a distal end 6255and defines a lumen therethrough (not shown). The proximal end 6253 ofthe valve actuator 6254 is configured to move or puncture the gas reliefvalve 6328 to move the gas relief valve 6328 between its firstconfiguration and its second configuration. The distal end 6255 of thevalve actuator 6254 is coupled to the housing 6110. In use, when theauto-injector 6002 is actuated, the gas chamber 6120 is placed in fluidcommunication with the compressed gas source 6412, thereby allowing apressurized gas to flow into the gas chamber 6120. The force produced bythe pressurized gas on the surface 6322 of the movable member 6312causes the movable member 6312 to move within the housing 6110 and themedicament container 6262, as shown in FIG. 52. As a result, the needle6212 is extended through the housing 6110 and the medicament is injectedvia the needle 6212.

When the movable member 6312 reaches a predetermined position within thehousing 6110, the proximal end 6253 of the valve actuator 6254 puncturesthe gas relief valve 6328, thereby causing the gas relief valve 6328 tomove irreversibly into its second configuration. In this manner,pressurized gas flows from the gas chamber 6120 to the area outside ofthe gas chamber 6128 through the opening 6326, as shown by the arrows g.The pressurized gas also flows from the area outside of the gas chamber6128 to an area outside of the housing 6129 through the lumen defined bythe valve actuator 6254. In this manner, the valve actuator 6254 definesa portion of the gas release path.

As shown in FIG. 53, when the pressurized gas flows out of the gaschamber 6120, the pressure exerted on the surface 6322 of the movablemember 6312 decreases. Accordingly, the force exerted by the biasingmember 6350 is sufficient to move the movable member 6312 proximallywithin the housing 6110, as indicated by arrow V, such that the needle6212 is retracted into the housing 6110. Because the gas relief valve6328 remains in its second configuration during retraction, the opening6326 remains in fluid communication with the gas chamber 6120 and thearea outside of the gas chamber 6128 independent of the position of themovable member 6312.

Additionally, the arrangement of the valve actuator 6254 can control thedistance through which the movable member 6312 moves within themedicament container 6262 (i.e., the stroke of the movable member), andtherefore the amount of medicament injected. As shown in FIG. 51, thestroke of the movable member 6312 is a function of the distance betweenthe length L1 of the valve actuator 6254 and the length L2 of themovable member 6312 in its initial position. Accordingly, the stroke ofthe movable member 6312 can be controlled by varying the length L1 ofthe valve actuator 6254 and/or the length L2 of the movable member 6312in its initial position.

The proximal end portion 6316 and the distal end portion 6318 are shownin FIGS. 51-53 as being separate components that are coupled together toform the movable member 6312. Such construction allows flexibilityduring manufacturing. For example, in some embodiments, the medicamentcontainer 6262 and the distal end portion 6318 are assembled in asterile environment and later coupled to the proximal end portion 6316in a non-sterile environment. In other embodiments, the two-piecearrangement of the movable member 6312 provides flexibility in settingthe length L2. For example, when a greater dosage of medicament isrequired, a shim or spacer (not shown) can be placed in the assemblyjoint between the proximal end portion 6316 and the distal end portion6318 to increase the length L2.

Although the stroke of the movable member 6312, and therefore the amountof medicament injected, is shown and described as being controlled byconfiguring the valve actuator 6254 to actuate the gas relief valve 6328when the movable member 6312 has moved a predetermined distance withinthe medicament container 6262, in other embodiments, any suitablemechanism for controlling the stroke of the movable member can be used.For example, the auto-injector 3002 shown and described above isconfigured so that the movable member 3312 contacts the carrier 3250 tolimit the stroke of the movable member 3312. In other embodiments, thestroke of the movable member can be limited by including a protrusionwithin the medicament container, such as a necked portion, that limitsthe motion of the piston within the medicament container. In otherembodiments, the housing can include a protrusion to limit the stroke ofthe movable member. In yet other embodiments, a combination of each ofthe above methods for controlling the stroke of the movable member canbe employed.

As discussed above, the valve actuator need not mechanically actuate thegas relief valve. For example, FIGS. 54 and 55 are schematicillustrations of a portion of an auto-injector 7002 having apneumatically actuated gas relief valve 7328. Because the auto-injector7002 is similar to the auto-injectors described above, only the gasrelief mechanism is discussed in detail. The auto-injector 7002 includesa housing 7110, a movable member 7312 and a gas relief valve 7328. Asdescribed above, the movable member 7312 includes a proximal end portion7316 that includes a surface 7322 that defines a portion of a boundaryof a gas chamber 7120. The proximal end portion 7316 also includes aseal 7314 that engages a portion the housing 7110 to fluidically isolatethe gas chamber 7120.

The housing 7110 includes a side wall 7122 that defines a portion of thegas chamber 7120. The side wall 7122 defines a first passageway 7152,which can be selectively placed in fluid communication between the gaschamber 7120 and an area outside of the housing 7129. The firstpassageway 7152 includes an opening 7153 into the gas chamber 7120 thatis defined proximal to the movable member 7312. The side wall 7122defines a second passageway 7156 that is substantially parallel to theside wall 7122 and intersects the first passageway 7152. The secondpassageway 7156 includes an opening 7157 selectively disposable withinthe gas chamber 7120 depending on the position of the movable member7312. The opening 7157 is defined distally from the opening 7153.

The gas relief valve 7328 includes a valve body 7360, a spring 7368 anda spring retainer 7370. The valve body 7360 is movably disposed withinthe second passageway 7156 and has a first position (FIG. 54) and asecond position (FIG. 55). The spring retainer 7370 is disposed withinthe second passageway 7156 and engages one end of the spring 7368. Thesecond end of the spring 7368 engages a proximal end portion 7362 of thevalve body 7360. In this manner, the valve body 7360 is biased in itsfirst position, such that a distal end portion 7364 of the valve body7360 engages a shoulder 7158 defined by the second passageway 7156.

When the valve body 7360 is in its first position, the valve body 7360obstructs the first passageway 7152, thereby fluidically isolating thegas chamber 7120 from the area outside of the housing 7129. As themovable member 7312 moves distally within the housing 7110, as shown byarrow W, the seal 7314 uncovers the opening 7157 of the secondpassageway 7156. This allows pressurized gas from the gas chamber 7120to flow into the second passageway 7156 and exert a force on the distalend portion 7364 of the valve body 7360. When force produced by thepressurized gas exceeds the force produced by the spring 7368, the valvebody 7360 moves proximally within the second passageway 7156, as shownby arrow X. In this manner, the opening 7153 of the first passageway7152 is uncovered, thereby allowing fluid communication between the gaschamber 7120 and the area outside of the housing 7129.

The proximal end portion 7362 of the valve body 7360 includes aprojection 7366 designed to engage the spring retainer 7370 therebymaintaining the valve body 7360 in its second position. Accordingly,when the movable member 7312 moves proximally within the housing 7110(i.e., the retraction operation) and the opening 7157 is covered by theseal 7314, the valve body 7360 will not return to its firstconfiguration. In this manner, the gas chamber 7120 remains in fluidcommunication with the area outside of the housing 7129 regardless ofthe position of the movable member 7312, thereby ensuring that the gaschamber 7120 is fully exhausted.

Although the auto-injectors shown and described above include a gasrelief valve having a first configuration in which the gas chamber isfluidically isolated and a second configuration in which the gas chamberis in fluid communication with an area outside the gas chamber, in someembodiments, an auto-injector can include a gas relief valve having morethan two configurations. For example, in some configurations, anauto-injector can include a gas relief valve having a fully closedconfiguration, a fully opened configuration and a partially openedconfiguration. In this manner, the gas relief valve can be used toregulate the pressure within the gas chamber and/or the flow of thepressurized gas from the gas chamber. Such regulation can be tailored tooptimize the needle insertion and/or the medicament injection operations(i.e., to ensure that the needle insertion is as painless as possible,that the medicament absorption profile is optimal, etc.).

Although the auto-injectors shown and described above include a gasrelief valve that irreversibly changes from a first configuration inwhich the gas chamber is fluidically isolated to a second configurationin which the gas chamber is in fluid communication with an area outsidethe gas chamber, in some embodiments an auto-injector can include a gasrelief valve configured to irreversibly change between the firstconfiguration and the second configuration throughout the insertionand/or injection cycle. For example, in some embodiments, anauto-injector can include a gas relief valve that repeatedly cyclesbetween its fully opened and its fully closed configurations during asingle injection event. Such an arrangement also allows the gas reliefvalve to be used to regulate the pressure within the gas chamber and/orthe flow of the pressurized gas from the gas chamber.

FIG. 56 is a schematic illustration of an auto-injector 8002 in whichthe gas relief valve 8328 has multiple different configurations, the gasrelief valve 8328 being shown in a first configuration. FIGS. 57-60 areschematic illustrations of a portion of the auto-injector 8002 in whichthe gas relief valve 8328 is in a second through a fifth configuration,respectively. Because the auto-injector 8002 is similar to theauto-injectors described above, only the gas relief mechanism isdiscussed in detail.

The auto-injector 8002 includes a housing 8110, a movable member 8312, amedicament container 8262 and a gas relief valve 8328. The medicamentcontainer 8262 is movably disposed within the housing 8110 and defines alongitudinal axis Lm. A needle 8212 is coupled to and can be placed influid communication with the medicament container 8262. As describedabove, the medicament container 8262 can be moved along its longitudinalaxis Lm between a first position (FIG. 56) and a second position. Whenthe medicament container 8262 is in its first (or retracted) position,the needle 8212 is disposed within the housing 8110. When the medicamentcontainer 8262 is in the second position, at least a portion of theneedle 8212 extends outside of the housing 8110.

The movable member 8312 includes a proximal end portion 8316 and adistal end portion 8318. As described above, the proximal end portion8316 includes a surface 8322 that, together with the housing 8110,defines a gas chamber 8120. The proximal end portion 8316 also definesan opening 8326 therethrough, which can be selectively placed in fluidcommunication with the gas chamber 8120 and an area outside of the gaschamber 8128. The distal end portion 8318 is movably disposed within themedicament container 8262.

The gas relief valve 8328 includes a frangible seal 8361 and a valvebody 8360. The frangible seal 8361 is coupled to the movable member 8312adjacent the opening 8326. When the gas relief valve 8328 is in itsfirst configuration (FIG. 56) the frangible seal 8361 fluidicallyisolates the gas chamber 8120 from the area outside of the gas chamber8128. When gas relief valve 8328 is in its second through fifthconfigurations (FIGS. 57-60), the frangible seal 8361 is moved orpunctured, which as described below, can allow fluid communicationbetween the gas chamber 8120 and the area outside the gas chamber 8128via the opening 8326. The valve body 8360 is coupled to the housing 8110and is configured to be disposed within the opening 8326 when themovable member 8312 moves distally within the housing 8110. The valvebody includes a first portion 8362, a second portion 8364, a thirdportion 8366 and a fourth portion 8367.

The operation of the auto-injector 8002 and the various configurationsof the gas relief valve 8128 are discussed with reference to FIG. 61,which shows a plot of the pressure within the gas chamber 8120 as afunction of the position of the movable member 8312. In FIG. 61, theposition of the movable member 8312, which also corresponds to theconfiguration of the gas relief valve, is represented on the x-axis. Thepressure within the gas chamber 8120 is represented on the y-axis.

In use, when the auto-injector 8002 is actuated, a pressurized gas flowsfrom a compressed gas source 8412 (see FIG. 56) into the gas chamber8120, causing the movable member 8312 to move distally within thehousing. The movable member 8312 moves the medicament container 8262between its first and its second position (the “needle insertion”operation). The needle insertion operation is shown in FIG. 61 as regionAA. As shown in FIG. 57, towards the end of the needle insertionoperation, the movable member 8312 is positioned such that the firstportion 8362 of the valve body 8360 moves or punctures the frangibleseal 8361, thereby placing the gas relief valve 8128 in its secondconfiguration (point CC on the plot in FIG. 61). When the gas reliefvalve is in its second configuration, the gas chamber 8120 is in fluidcommunication with the area outside the gas chamber 8128 via the opening8326. Accordingly, the pressure within the gas chamber 8120 is reduced,as indicated in FIG. 61. Reducing the pressure during the needleinsertion operation can, for example, reduce patient discomfort duringthe needle insertion operation.

When the medicament container 8262 reaches its second position, themovable member 8312 continues to move distally within the medicamentcontainer 8262, as shown by arrow Y, to inject the medicament throughthe needle 8212. The medicament injection operation is shown in FIG. 61as region BB. As shown in FIG. 58, during the beginning of the injectionoperation, the movable member 8312 is positioned such that the secondportion 8364 of the valve body 8360 is disposed within the opening 8326,placing the gas relief valve 8128 in its third configuration (point DDon the plot in FIG. 61). The second portion 8364 of the valve body 8360is configured to fit within the opening 8326 such that the gas chamber8120 is substantially fluidically isolated from the area outside of thegas chamber 8128. Because pressurized gas continues to flow from thecompressed gas source (not shown) into the gas chamber 8120, byfluidically isolating the gas chamber 8120, the pressure within the gaschamber 8120 will no longer decrease, but will instead remain constantor increase slightly.

During the middle portion of the injection operation, the movable member8312 is positioned such that the third portion 8366 of the valve body8360 is disposed within the opening 8326, placing the gas relief valve8128 in its fourth configuration (point EE on the plot in FIG. 61). Thethird portion 8366 of the valve body 8360 is shaped to allow acontrolled amount of pressurized gas to flow from the gas chamber 8120to the area outside the gas chamber 8128 via the opening 8326. Saidanother way, the third portion 8366 of the valve body 8360 and theopening 8326 define a flow passageway between the gas chamber 8120 andan area outside the gas chamber 8128. The flow passageway varies basedon the shape of the third portion 8366 of the valve body 8360. Forexample, a narrow shaped third portion 8364 results in a larger flowarea, whereas a larger shaped third portion 8366 results in a smallerflow area. In this manner, the flow area can be varied as a function ofa longitudinal position of the movable member 8312. The third portion8366 can be shaped such that the pressurized gas entering the gaschamber 8120 from the compressed gas source (not shown) is equal to thepressurized gas exiting the gas chamber 8120. Accordingly, as shown inFIG. 61, the pressure within the gas chamber 8120 can be substantiallyconstant throughout the injection operation.

At the end of the injection operation, the movable member 8312 ispositioned such that the fourth portion 8367 of the valve body 8360 isdisposed within the opening 8326, placing the gas relief valve 8128 inits fifth configuration (point FF on the plot in FIG. 61). The fourthportion 8367 of the valve body 8360 is considerably smaller than thethird portion 8366, thereby allowing a significant amount of pressurizedgas to flow from the gas chamber 8120 to the area outside the gaschamber 8128 via the opening 8326. Said another way, when the fourthportion 8367 of the valve body 8360 is within the opening 8326, thevalve 8128 is “fully opened.” Accordingly, as shown in FIG. 61, thepressure within the gas chamber 8120 decreases rapidly. In someembodiments, the rapid drop in pressure allows the movable member 8312to be retracted by a biasing member. In this manner, the needle 8212 isalso retracted into the housing 8110, thereby minimizing post-injectionhazards.

Although the gas relief valve 8128 is described as being a mechanicalcomponent that varies a flow area as a function of the movable member,in other embodiments, the gas relief valve can be any suitable type ofvariable area valve. For example, in some embodiments, a gas reliefvalve can be an electrically operated spool valve.

While the valve body 8360 is shown as having four distinct regionscorresponding to four variably functional positions, in otherembodiments, the valve body can have fewer or greater distinct regionscorresponding to a different number of functional positions.Additionally, the shapes and sizes of the illustrated valve bodyportions 8362, 8364, 8366 and 8367 are shown by way of example only. Insome embodiments, the valve body can be shaped according to a desiredpressure and/or injection profile.

Although the auto-injectors are shown and described above as having asingle gas chamber and a single gas relief valve, in some embodiments,an auto-injector can include any number of gas chambers and/or gasrelief valves. For example, in some embodiments, an auto-injector caninclude a compressed gas source, an auxiliary gas chamber and a primarygas chamber. In a similar manner as described above, the compressed gassource can be selectively placed in fluid communication with theauxiliary gas chamber, thereby allowing the auxiliary gas chamber to befilled with a pressurized gas. The auto-injector can include a first gasrelief valve configured to selectively place the auxiliary gas chamberin fluid communication with the primary gas chamber. When pressurizedgas is conveyed from the auxiliary gas chamber into the primary gaschamber via the first gas relief valve, the gas pressure within theprimary gas chamber causes an injection event, as described above. Theauto-injector can also include a second gas relief valve configured toselectively place the primary gas chamber in fluid communication with anarea outside of the auto-injector housing. By including an auxiliary gaschamber, which can be vented independently from the primary gas chamber,the auto-injector can be configured as a multiple-use injector.

Similarly, while the auto-injectors are shown and described above ashaving an area outside of the gas chamber that is in fluid communicationwith an area outside of the housing, in some embodiments, the areaoutside of the gas chamber need not be vented to the atmosphere. Forexample, in some embodiments, an auto-injector can include an areaoutside of the gas chamber that is in fluid communication with asecondary gas chamber.

While various embodiments of the invention have been described above, itshould be understood that they have been presented by way of exampleonly, and not limitation. Where methods described above indicate certainevents occurring in certain order, the ordering of certain events may bemodified. Additionally, certain of the events may be performedconcurrently in a parallel process when possible, as well as performedsequentially as described above.

Although various embodiments have been described as having particularfeatures and/or combinations of components, other embodiments arepossible having a combination of any features and/or components from anyof embodiments where appropriate. For example, in some embodiments, agas relief mechanism can include an first opening defined by the movablemember that can be selectively placed in fluid communication with thegas chamber and an area outside of the gas chamber and a second openingdefined by the housing that can be selectively placed in fluidcommunication with the gas chamber and an area outside of the housing.

What is claimed is:
 1. An apparatus, comprising: a housing defining agas chamber; a medicament container disposed within the housing; aneedle fluidically coupled to the medicament container, the needleconfigured to move between a first needle position, in which the needleis disposed within the housing, and a second needle position in which aportion of the needle extends from the housing; a retraction springconfigured to bias the needle towards the first needle position; anexpandable assembly including a flexible member and a distal member, theflexible member configured to transition between a collapsedconfiguration and an expanded configuration; and an energy storagemember configured to produce a pressurized gas within the gas chamber,the pressurized gas exerting a force to move the needle from the firstneedle position to the second needle position and to move the distalmember of the expandable assembly within the medicament container toconvey a medicament from the medicament container via the needle, theflexible member of the expandable assembly configured to actuate a valveto release the pressurized gas from the gas chamber when the flexiblemember is transitioned from the collapsed configuration to the expandedconfiguration.
 2. The apparatus of claim 1, wherein the flexible memberhas a first size when in the collapsed configuration and a second sizewhen in the expanded configuration, the flexible member beingtransitioned from the collapsed configuration to the expandedconfiguration when the distal member of the expandable assembly moveswithin the medicament container such that the flexible-member actuatesthe valve after the medicament is conveyed from the medicamentcontainer.
 3. The apparatus of claim 1, wherein: a length of theflexible member increases when the distal portion of the expandableassembly moves within the medicament container to convey the medicament.4. The apparatus of claim 3, wherein: the flexible member transfers atensile force from the distal portion to the valve to actuate the valvewhen the distal portion has moved the predetermined distance.
 5. Theapparatus of claim 1, wherein the flexible member is one of a string, anelastic member or a biasing member.
 6. An apparatus, comprising: ahousing defining a gas chamber; a medicament container disposed withinthe housing; a needle fluidically coupled to the medicament container,the needle configured to move between a first needle position, in whichthe needle is disposed within the housing, and a second needle positionin which a portion of the needle extends from the housing; a pusherconfigured to push the medicament from the medicament container andthrough the needle to convey the medicament out of the medicamentcontainer; a retraction spring configured to bias the needle towards thefirst needle position; a flexible release member having a proximalportion and a distal portion, the flexible release member configured totransition between a collapsed configuration and an expandedconfiguration; and an energy storage member configured to produce apressurized gas within the gas chamber, the pressurized gas exerting aforce to move the needle from the first needle position to the secondneedle position and to move the pusher within the medicament containerto convey a medicament from the medicament container via the needle, theflexible release member configured to actuate a valve to release thepressurized gas from the gas chamber when the flexible release member istransitioned from the collapsed configuration to the expandedconfiguration.
 7. The apparatus of claim 6, wherein the flexible releasemember has a first size when in the collapsed configuration and a secondsize when in the expanded configuration, the flexible release memberbeing transitioned from the collapsed configuration to the expandedconfiguration when the distal portion of the expandable assembly moveswithin the medicament container such that the flexible release memberactuates the valve after the medicament is conveyed from the medicamentcontainer.
 8. The apparatus of claim 6, wherein: a length of theflexible release member increases when the pusher moves within themedicament container to convey the medicament; and the proximal portionof the flexible member is configured to actuate the valve when thedistal portion of the flexible member moves a predetermined distancewithin the medicament container.
 9. The apparatus of claim 6, wherein:the flexible release member is a tension member; and the tension membertransfers a tensile force from the distal portion to the valve via theproximal portion to actuate the valve when the distal portion has movedthe predetermined distance.
 10. The apparatus of claim 6, wherein: alength of the flexible release member increases when the pusher moveswithin the medicament container to convey the medicament; the retractionspring causes the needle to move from the second needle position towardsthe first needle position after the pressurized gas is released from thegas chamber; and the length of the flexible release member decreaseswhen the needle moves from the second position towards the first needleposition.
 11. A method of delivering a medicament from a medicalinjector, comprising: placing a distal end surface of a base of themedical injector into contact with a body, the medical injectorincluding a housing, a medicament container within the housing, aplunger within the medicament container, a needle fluidically coupled tothe medicament container, an energy storage member, a valve, and aflexible member coupled between the plunger and the valve; and actuatingthe medical injector to cause the energy storage member to produce apressurized gas within a gas chamber defined by the housing, thepressurized gas exerting a force to: A) move the needle from a firstneedle position, in which the needle is within the housing, to a secondneedle position, in which a portion of the needle is outside of thehousing and B) move the plunger within the medicament container toconvey the medicament from the medicament container via the needle, theflexible member transitioning from a first configuration to a secondconfiguration when the plunger moves within the medicament container,the flexible member actuating the valve to release the pressurized gasfrom the gas chamber when the flexible member is transitioned from thefirst configuration to the second configuration.
 12. The method of claim11, wherein: the medical injector includes a retraction spring withinthe housing, the retraction spring causing the needle to move towardsthe first needle position after the pressurized gas is released from thegas chamber.
 13. The method of claim 11, wherein the actuating includespressing the base against a target surface of the body to move the baserelative to the housing.
 14. The method of claim 13, further comprising:removing, before the placing, an actuator guard from an end portion ofthe housing, the actuator guard configured to limit movement of the basewhen the actuator guard is coupled to the housing.
 15. The method ofclaim 11, wherein a length of the flexible member increases when theflexible member transitions from the first configuration to the secondconfiguration.
 16. The method of claim 15, wherein: a proximal endportion of the flexible member is coupled to the valve; and the lengthof the expandable assembly increases when the plunger moves within themedicament container, the proximal end portion of the flexible memberactuating the valve when the plunger moves a predetermined distancewithin the medicament container.
 17. The method of claim 16, wherein theflexible member is one of a string, an elastic member or a biasingmember.
 18. The method of claim 17, wherein: a portion of the valve iswithin a vent opening defined by the housing to fluidically isolate thegas chamber from an external volume when the valve is in a first valveposition, the proximal end portion of the flexible member moving thevalve to a second valve position when the flexible member istransitioned to its second configuration, the gas chamber in fluidcommunication with the external volume via the vent opening when thevalve is in the second valve position.
 19. The method of claim 11,wherein the medicament is any one of a drug or a biologic product. 20.The method of claim 11, wherein the medicament is a biologic productcontaining at least one of a hormone or an antidote.
 21. The method ofclaim 11, wherein the medicament is epinephrine.
 22. A method ofdelivering a medicament from a medical injector, comprising: moving anactuator of a medical injector relative to a housing of the medicalinjector, the medical injector including a housing, a medicamentcontainer within the housing, a plunger within the medicament container,a needle fluidically coupled to the medicament container, an energystorage member, a valve, and a flexible member coupled between theplunger and the valve; producing, from the energy storage member inresponse to the moving the actuator, a pressurized gas within a gaschamber defined by the housing; moving, in response to the pressurizedgas, the needle from a first needle position, in which the needle iswithin the housing, to a second needle position, in which a portion ofthe needle is outside of the housing; moving, in response to thepressurized gas, the plunger within the medicament container to conveythe medicament from the medicament container via the needle;transitioning the flexible member from a first configuration to a secondconfiguration when the plunger moves within the medicament container;actuating the valve to release the pressurized gas from the gas chamberwhen the flexible member is transitioned from the first configuration tothe second configuration; and
 23. The method of claim 22, wherein themedical injector includes a retraction spring, the method furthercomprising: moving the needle towards the first needle position afterthe pressurized gas is released from the gas chamber.
 24. The method ofclaim 22, wherein the transitioning the flexible member includesincreasing a length of the flexible member.
 25. The method of claim 24,wherein the flexible member is one of a string, an elastic member or abiasing member.
 26. The method of claim 25, wherein: a portion of thevalve is within a vent opening defined by the housing to fluidicallyisolate the gas chamber from an external volume; the actuating the valveincludes moving the portion of the valve out of the vent opening toplace the gas chamber in fluid communication with the external volume.27. The method of claim 26, wherein the medical injector includes acover disposed about the opening, the cover configured to limit accessto the opening from the external volume.
 28. The method of claim 25,wherein: a proximal end portion of the flexible member is coupled to thevalve; and the length of the expandable assembly increases when theplunger moves within the medicament container, the proximal end portionof the flexible member actuating the valve when the plunger moves apredetermined distance within the medicament container.
 29. A method,comprising: placing an outer housing of a medical injector into contactwith a body, the outer housing enclosing an inner housing, a medicamentpusher, and a gas container storing a compressed gas, the medicamentpusher at least partially disposed within the inner housing and incontact with a flexible release member disposed therein, the flexiblerelease member being in a first configuration associated with apre-activation status prior to placing the outer housing into contactwith the body; injecting a medicament contained within the inner housinginto the body, the injecting including releasing at least a portion ofthe compressed gas from the gas container into a gas chamber defined atleast in part by the outer housing, the force associated with thecompressed gas released into the gas chamber being sufficient to move atleast the pusher in a distal direction toward the body to inject themedicament into the body, the flexible release member configured to movefrom the first configuration toward a second configuration along withthe medicament pusher moving in the distal direction; and expelling atleast a portion of the compressed gas released into the gas chamber outof the outer housing through a release mechanism, the expellingincluding the flexible release member engaging the release mechanismwhen in the second configuration after movement of the medicamentpusher.
 30. The method of claim 29, wherein: the releasing at least aportion of the compressed gas from the gas container moves themedicament pusher from a first position to a second position to expelthe medicament from the medicament container.
 31. The method of claim29, wherein: the placing the outer housing includes placing a contactmember movably coupled to a distal end portion of the outer housing incontact with a target surface of the body; and the flexible releasemember configured to move from the first configuration to the secondconfiguration when the contact member is stationary relative to theouter housing.
 32. The method of claim 29, wherein the outer housing isthe outer housing of an auto-injector, the inner housing is a medicamentcontainer containing the medicament, the method further comprising:removing, before the placing, an actuator guard from an end portion ofthe outer housing, the actuator guard configured to limit movement of anactuator when the actuator guard is coupled to the outer housing, theactuator configured to release the compressed gas from the gas containerinto the gas chamber.
 33. The method of claim 32, wherein: theauto-injector further includes a needle coupled to the medicamentpusher; an end portion of the needle being moved from a first needleposition within the outer housing to a second needle position outside ofthe outer housing in response to movement of the medicament pusher; andthe injecting the medicament includes injecting the medicament into thebody via the needle when the needle is in the second needle positionoutside of the outer housing.